Name: Mustafar
Region: Outer Rim Territories, Western Reaches
Sector: Atravis sector
System: Mustafar system
Suns: 1: Priate
Orbital position: 3, overlapping orbit
Moons: 0
Grid coordinates: L-19
Trade routes: Tosste Spur
Distance from Core: 53,000 light-years
Rotation period: 36 standard hours
Orbital period: 412 local rotations
Class: Terrestrial (historic), Wasteland (Imperial Era)
Diameter: 4,200 kilometers (2,610 miles)
Atmosphere: Type II (breath mask suggested)
Climate: Hot, ash-laden, and stormy
Gravity: Standard
Primary terrain: Caves, Forests, Glens, Lava seas, rivers, and pits (35% of surface), Molten rock plains, Obsidian mountain ranges and shores, Volcanoes
Surface water: 0%
Points of interest: Berken's Flow, Black Sun fortress, Burning Plains, Central volcano, Crystal Flats, Darth Sidious's secret facility, Gahenn Plains, Corvax Fen, Corvax Fortress, Crystal Flats, Fortress Vader, Imperial base, Sith cave, Sith temple, The Last Resort, Mensix Mining Facility, Mustafar droid factory, Mustafarian Mining Complex, Smoking Forest, Tulrus Island, Ziton's palace
Flora: Irontree, Kahel cave fungus
Fauna: Darkghast, Fire rat, Krishel, Lava eel, Lava flea, Lava nymph, Lizard-crow, Mustafar beetle, Roggwart (immigrated), Spark-roach, Xandank
Native species: Mustafarian
Immigrated species: Falleen, Human, A large variety of other species
Primary language(s): Mustafarian
Population: Approximately 15,000–20,000
Demonym: Mustafarian
Major cities: Fralideja (capital), Zitontown
Major imports: Water
Major exports: Dolovite, Lava, minerals, and metal ore

Description:
World of fire
A small planet located in the Atravis sector of the Outer Rim Territories within the eponymous system, Mustafar was situated on the Tosste Spur trade route, off the Rimma Trade Route, in grid square L-19 of the Standard Galactic Grid. Located 53,000 light-years from the galaxy's Core, Mustafar was once a lush world thriving with life, thanks to the power of the Bright Star, which nourished what came to be known as a garden world.

Millennia before the Imperial Era, however, Mustafar become an unstable volcanic world, with lava constituting 35% of its surface. Occupying the third orbit of its system around the primary star Priate, the tortured planet was powerful in the dark side of the Force, and, along with its valuable mineral allotropes that surfaced from the planet core as well as its obscurity to the wider galaxy, attracted various off-world interests that exploited the molten planet. Mustafar remained a fiery world until the destruction of the Bright Star, at which point the planet was allowed to regrow. Such different states of the world led some to believe that spiritual forces were the catalysts to the changes in Mustafar's nature.

Heart of lava
Deep underground, Mustafar contained lava lakes from which fumes drifted up to surface-level facilities; such fumes played tricks with the minds of organics who inhaled it, giving rise to what Lellis referred to as "shadows of the mind"—visions of fears and doubts that could manifest as ghosts of the past. Such gases were most potent around the vicinity of the Mustafarian Mining Complex, and sustained exposure to it drove an individual insane. Repulsor vents were thus installed at the Mining Complex to prevent such toxic fumes from rising to indoor facilities and being inhaled by those within.

Orbiting close to the gas giant Jestefad, with which it was twinned, Mustafar was constantly pulled by the gravitational force of the nearby planet, which nearly captured the smaller world as its moon; only the counterbalancing gravitational pull from the more remote gas giant of Lefrani prevented it from being claimed as Jestefad's orbit. In spite of such, Mustafar possessed a standard gravity. The influence of the massive magnetic field of Mustafar's larger twin, however, resulted in its hellish volcanic landscape, as the power of Jestefad's gravitational force caused massive tidal disruption that heated Mustafar's interior. Along with being engulfed in a constant gravimetric battle, Mustafar housed an unstable core that caused groundquakes powerful enough to split the planet's continents apart, and its split tectonic plates allowed the planet's searing magma to push through to the surface, creating a volcanic hot spot visible as a bright red cluster from space.

While great portions of the planet were always in motion, one of the few constant features was the central volcano. Lava poured out of the spot at nearly 100,000 litres per second and pooled at the giant volcano's base. To the north was a region named the Burning Plains, which boasted heavy volcanic activity. Another region earned its nickname, the Smoking Forest, as smoke spewed from its tree-like rock chimneys. Mustafar's Berken's Flow was the largest lavafall in the galaxy, while a landmass named Tulrus Island was surrounded by tall mountains.

The young world's instability churned magma carrying ores with unique and valuable minerals to its surface, attracting business interests from various galactic mining conglomerates such as the Mining Guild to exploit the mineral wealth of the otherwise untouched world. The searing magma that bubbled beneath the surface flooded the planet, covering it in oceans and rivers of lava. Geothermal energy was the main power source of the Techno Union's mining complex on the planet, and the lava flows that coated the rocky terrain left behind traces of flood basalt. At 800°C (1500°F), Mustafar's lava, while still very hot, had a lower temperature than that found on other worlds due to unusual mineral allotropes that were molten at lower temperatures. Nevertheless, patches of Mustafar began to cool in the decades leading up to 35 ABY.

Tempestuous skies
Mustafar's atmosphere was influenced by the breath of its volcanoes and Jestefad's massive magnetic field. Along with cyclonic-force updrafts and thermal currents, titanic lightning storms made up the planet's unfriendly skies. Turbulent and ash-laden, the atmosphere was also hot and chemical, consisting of thick clouds of black smoke and allowing for choking ash to fall like rain. Lava processing operations created toxic gas by-products, and a noxious air cast the world in a hazy fog. Thus, Mustafar was classified as a world with a Type II atmosphere, wherein the usage of a breath mask was recommended.

The frequent electromagnetic interference and lightning storms in the atmosphere led to signal loss and noise respectively, though the effects of Mustafar's hectic skies could be reduced through the use of dedicated dampers. However, electromagnetic interference also posed a significant risk for off-world arrivals and departures. Those caught in one such storm without the assistance of specially shielded surface-level landing equipment—which included energy-shielded landing pads and guidance and tractor beams—found, at best, their starship's scanners rendered useless and navigational equipment and control systems interfered with. In certain cases, a ship was torn apart as Mustafar was by Lefrani and Jestefad. Ships were additionally threatened by Mustafar's intense heat and incendiary ash, though any damage could be prevented should a vessel be equipped with sufficiently powerful energy shields.

Fauna and flora
Despite its hellish environment, Mustafar was teeming with life, a home to fragile but determined organisms all connected through the Force. In the solid rock betwixt lava flows, there lived mammalian, reptillian, as well as insect species. The extremophile creatures of the planet had adapted to Mustafar's desolation and become indomitable.

The large insectoids known as lava fleas had developed a tough exoskeleton that protected them from the fiery devastation of the world. They were known to eat away at the planet's crust and were commonly used as mounts by the sentient Mustafarians, who were insectoids themselves. Other species found on the planet included lizard-crows, which could be found in Mustafar's lava fields; these creatures were often scared away by what the Mustafarians referred to as "molten men." Spark-roaches and rodents called fire rats also called Mustafar their home, the latter of which were known to gnaw on the lava crystals that formed on the planet.

Similar to lava fleas, xandanks were another insectoid species well protected by their armor; those beings were predators native to Mustafar that hunted in packs. Tough, semi-sentient creatures known as roggwarts hunted the planet's tunnels and lava tubes in search of xandanks, as well as for giant, man-eating lava eels. Despite the danger of roggwarts, they could be domesticated with the proper training and were imported to Mustafar to work in the planet's mines.

By 3 BBY, a roggwart known as Kongo the Disembowler was employed to keep the dolovite mine tunnels free of xandanks and lava eels. Kongo was reputedly the last of his kind by between 0 and 1 ABY, although it may have been said in an effort to make the roggwart seem more mysterious and exotic.

Life-forms lethal and unswerving
Much like the planet itself, some of the creatures found on Mustafar were especially deadly. Highly aggressive creatures posed a significant hazard on the planet due to its scarce resources. The fearsome darkghast, similar in some respects to the rancors of Dathomir, was a multi-limbed carnivore that could be found beneath the world's rocky surface. Lava nymphs, winged creatures that lived in hives, could also be found in the planet's caverns. Considered to be vermin, the creatures' insides were filled with lava, which they were able to spit out when provoked. A species of beetle also inhabited the planet; starting life as a small larva, the creature developed a defense mechanism by the time it reached adulthood that allowed it to warn its brood by exploding. Burrowing quadrupeds known as krishels inhabited Mustafar's labyrinthine caverns and tunnels. Those strong, hardshelled creatures were hunted by the Mustafarians.

Although the lush vegetation that once covered the planet eventually disappeared beneath fire and ash, Mustafar was not devoid of fungal and vegetal life. Hidden away from the world's searing lava rivers, kahel cave fungi grew underground. These organisms were deeply symbolic to the native Mustafarians and served as the inspiration for their mushroom-like architecture. Following the destruction of the Bright Star during the Imperial Era, life began to slowly creep back once again. By 35 ABY, barren irontrees could be found within the few places where fertile soil existed, such as the muggy marshland of Corvax Fen.

History
Cataclysm immortalized
In its ancient past, Mustafar was a lush and forested terrestrial planet, thriving with life through the Bright Star, the native Mustafarians' most sacred artifact that nourished the small garden world. Ancient legends said that offworlders led by Lady Corvax and her husband arrived at some point, living in harmony with the natives. However, the garden world came under attack, and Corvax's husband fell in battle. Unable to let go of her love, Corvax stole the Mustafarians' Bright Star in her pursuit of immortality, having thought it had the power to resurrect her husband from death.

Corvax created the Aeon Engine and encased the artifact within, although her actions ultimately resulted in the devastation of the planet; energies ruptured from the Bright Star, pushing Mustafar out of its original orbit. Legends claimed that due to a cataclysmic struggle between the Sith and the Jedi millennia before the Imperial Era, the orbit of the gas giant Lefrani was also shifted, and Mustafar entered an unusual and gravitationally crushing alignment between it and Jestefad's magnetic fields.

Mustafar's new, precarious orbit rendered it a volcanic wasteland as both gas giants pulled on tiny Mustafar, heating its interior in their attempts to claim Mustafar as their moon. The crust of the smaller world was also torn apart, allowing the flow of lava toward the planet surface. Very few species survived the cataclysm, with the homes of nearly all native species being destroyed. The remaining life-forms evolved short, tough bodies to endure the superheated clime, and the Mustafarians were forced to areas in Mustafar's north and near the equator. There, they adapted and evolved to the new realities of life on Mustafar. These events passed into legend, attracting Sith who were looking for the secrets of eternal life. Eventually, a Sith temple and a Sith shrine was built on the world.

A colony for mines and an outlaws' cove
Over three hundred years before the Clone Wars, the Techno Union came to own the planet and charged the Mustafarians rent. The Union provided the Mustafarians with tools to mine mineral allotropes for them, labor which served to pay their rent. Mixed with workers of a great variety of other species, Mustafarian miners lived in simple residences at dedicated though run-down mining towns, and were helped by Techno Union technology such as the Baktoid UH-XH repulsorlift-powered platforms, lava-processing centrifuges, electrorefining droids, and the DLC-13 mining droid to collect mineral-rich lava spewing from Mustafar's heated interior.

Over the centuries, however, Mustafarians became wary of technology that failed under the intense heat of their world and which had an inadequate melting point due to witnessing mechanical breakdowns. Such was the case for speeders, including the heavy-duty UH-XH, which were generally left to be operated by droids. Nevertheless, by the end of the Clone Wars, Mustafar had served as a literal gold mine for the Techno Union for almost three hundred standard-years.

Although Mustafar came to be known primarily for its mining activities, those desperate offworlders and law-evaders who were undeterred by the world's harsh conditions were drawn to it as a result of the obscure world's sparse population. Mustafar was also ideal for hiding or disposing items in secret.

Revenge of the Sith
During the Clone Wars, the Mustafarians aligned themselves with the Confederacy of Independent Systems. However, they were not fanatically committed to the cause, having only joined to secure themselves Separatist contracts, and life continued much as it had before. With members of the Jedi Order, the galaxy's guardians of peace and justice, focused on defeating the Separatists, law enforcement found itself in a declining state, especially in the infrequently patrolled Outer Rim. Thus, organizations of the criminal underworld flourished, including Black Sun, a syndicate led by a cabal of Falleen nobles with interplanetary influence. The Falleen operated from the shadows, establishing elusive holdings on Mustafar and headquartering themselves in a well-defended fortress on the world, where they regularly met and found the surrounding lava useful for the disposal of evidence. The native Mustafarians cared little for Black Sun, since most of their operations took place elsewhere in the galaxy. Hidden away from prying eyes, the Techno Union also produced battle droids behind their mining operations on the planet at the time of the Clone Wars.

Aside from skirmishes and lesser operations, fighting largely passed Mustafar by during the Clone Wars. In one instance, the planet bore witness to a plot to kidnap Force-sensitive children by bounty hunter Cad Bane, who deposited the children at a facility there for the Sith Lord Darth Sidious' plan to create an army of Force spies. However, Jedi Anakin Skywalker and Ahsoka Tano rescued the children, and the facility was destroyed by Sidious' nanny droids on the Sith's orders, ensuring the loss of any evidence of the plot's mastermind.

In 19 BBY, renegade Sith Lord Maul, his apprentice Savage Opress, and Pre Vizsla, the leader of the Mandalorian terrorist organization Death Watch, traveled to the Black Sun fortress with the intention of recruiting them into their criminal empire, the Shadow Collective. The Captain of the Guard, Ziton Moj, greeted them upon their arrival and led them to the Black Sun's leaders, headed by the Falleen Xomit Grunseit, who hailed from Mustafar. After negotiations with the leaders went sour, Savage beheaded all of them with his lightsaber. Moj became the new leader of the Black Sun, and joined with Death Watch, providing them with weapons, troops, and supplies.

The lost children
When Quinlan Vos was sent undercover as a bounty hunter to work alongside Dooku's former apprentice, Asajj Ventress, the pair was hired by the Pyke Syndicate to retrieve Marg Krim's wife, Tezzka Krim, and their children, Vram and Laalee, who were kidnapped by Black Sun and brought to their base on Mustafar in order to bribe the Pykes into joining Maul's Shadow Collective. The two traveled to Mustafar in the Ventress' ship Banshee and entered Zitontown seeking to gather information at the The Last Resort, the lone bar in the town. There, the pair interrogated a Falleen Black Sun enforcer and discovered where the prisoners were held. They infiltrated the lava-surrounded Black Sun fortress and rescued the children, though they later discovered that their mother was held in Ziton's palace. After the pair freed Tezzka, Moj had assembled his forces, which left Mustafar to attack the Pykes on Oba Diah.

Mirror of the soul
As the war's end drew nearer, Anakin Skywalker made a pact with the Sith Lord Darth Sidious for himself to gain the power to save his lover, Padmé Amidala, from leaving him by death at the cost of submitting his soul as Darth Vader, Sidious' new apprentice. The fallen Skywalker was then sent by his new master to dispatch of the Separatist leaders previously sequestered by Sidious to the Mustafarian Mining Complex on Mustafar, traveling with a green Eta-2 Actis-class light interceptor and his droid R2-D2. Darth Sidious hoped for Vader to be bathed in the dark side of the Force and emerge stronger than even him, ordering his apprentice to transmit the order to Separatist assets subsequent to wiping out the Separatist leaders for the Separatist Droid Army to be deactivated immediately, effectively ending the war and allowing his Sith Master's newly-established Galactic Empire to seize control of the galaxy.

A rumor spread over the fire plains of Mustafar that a Jedi Knight—a reputed protector of light, guardian of peace and life, and a hero of the Republic—had been spotted at the Mining Complex. The Mustafarian boy Kakan hoped to exact his dream of meeting a Jedi, and so approached the fallen Skywalker, who was viewing the eclipse of Mustafar's sun by Lefrani at the complex's balcony, just as Skywalker's massacre of the Separatists eclipsed the light of the Force within him.

However, Kakan saw that the figure was not the Jedi he expected. The fallen Jedi's eyes radiated such anger and hate that Kakan was compelled to run away, escaping to the complex's foundry. Kakan found the miner Lellis, who operated the facility's repulsor vents, releasing fumes from the depths of Mustafar that gave one illusions when inhaled. The potent fumes overwhelmed the fallen Skywalker with his fears, and Kakan and Lellis took advantage of the former Jedi's distraction to escape. However, as fear took hold of the boy, the two Mustafarians fell into a lava lake, though they were saved by a burst of Force power released by the fallen Skywalker in a bout of anger.

To not let go
Shortly after the slaughter of the Separatist leaders at the Techno Union mining complex's secret war room, Padmé Amidala arrived at Mustafar, having rushed to the volcanic world in the hope of saving her husband from falling further to the dark side. Her pleas fell on deaf ears, however, when Vader spotted Obi-Wan Kenobi emerging from the ship. In his anger and his inability to let go of Amidala, Vader incorrectly assumed that his wife had betrayed him to Kenobi. Thus, he strangled his pregnant wife through the Force, demonstrating to her that Skywalker was consumed by his lust for power and became Darth Vader.

Darth Vader then delivered an ultimatum that one was either with him or against him. Upon such a Sith trait of acting in absolutes, Vader was plagued by self-doubt and gave himself to the dark side, attacking his former friend and master; as he attempted to murder Kenobi, Vader bathed the remnants of Anakin Skywalker in the dark side of the Force that echoed from the Sith sanctum on Mustafar. Sabers clashed, and amidst the chaos, the shields protecting the mining facility were shut down, destroying parts of the building as well as the Lapiz Cutter, Separatist Council member Nute Gunray's personal shuttle.

Forced to fight across the lava streams, Vader was fueled by hatred and, in his hubris, the fallen Jedi went without regard to his own limitations, and fell to Kenobi's blade. As the Chosen One lost himself to the dark side, his remaining limbs were severed and his entire body suffered severe burns from one of Mustafar's many lava rivers.

Scarring legacies
The fallen Jedi's lightsaber was then taken by Kenobi, who left him to die on the sands of the river bank and took Amidala to a base on the asteroid field Polis Massa in order for her to give birth to her twins, Luke and Leia. Alhough charred and broken, Vader was recovered by Sidious, and he was brought back to Coruscant to be rebuilt with cybernetics at the Grand Republic Medical Facility with the technology of the acclaimed scientist Cylo, becoming encased in a suit of terrifying black armor.

Despite his survival, the events of Mustafar haunted Darth Vader throughout the age of the Empire, affecting the Sith's performance as the Emperor's primary enforcer. Seldomly, stories circulated amongst Mustafarians of a great Jedi duel on their world, although no evidence was given for such tales. Nevertheless, Mustafarians had knowledge of the former Jedi who slaughtered the Separatist leaders and nearly killed the boy Kakan and the miner Lellis, and whilst some thought that the fallen Jedi Knight was gone, some thought that he still remained in the mists of Mustafar. By the reign of the Empire from Darth Vader's castle years later, Lellis realized that his kind lived in the shadow of the fallen Jedi Knight, of Vader, since the fall of the Separatists.

Vader's domain
A short time after his loss to Kenobi, Vader returned to Mustafar under instructions from his master Darth Sidious. Vader was to bleed a kyber crystal he had obtained from the Jedi Master Kirak Infil'a, who he killed, in order to gain a crimson crystal for his new Sith lightsaber. He traveled to a cave strong in the dark side of the Force that contained the shrine erected by the ancient Sith and poured all of his pain and anger into the crystal, making it sing a hymn of darkness. With this new weapon, Vader returned to his master, and was believed by Sidious to be one step closer to becoming a true servant of the dark side.

Vader was later tasked by his master with hunting down surviving Jedi, and was sent to capture the former Jedi Chief Librarian Jocasta Nu at the Coruscant Jedi Temple. Master Nu possessed a memory crystal given to her by seekers of the Jedi Order that contained a list of potential Jedi Initiates from throughout the galaxy. After the new Sith apprentice took the list from a captive Nu, the latter told him that the Emperor's true purpose was to use it to create more agents like Vader, and the Jedi questioned what Vader truly desired while the Sith read the list. As seen by Vader, the list contained the names and locations of Force-sensitives, including Nik Lowe on Mustafar. Conflicted, Vader killed the librarian and destroyed the memory crystal, reporting back to the Emperor that he found nothing of interest on Nu.

Over a year after the battle against his former friend on Mustafar, the memory of Darth Vader burning on the volcanic slopes of Mustafar resurfaced in Obi-Wan Kenobi's thoughts along with other past happenings. Despite the pain inflicted by the memories of the past, Kenobi willed himself to let go of the series of events that led to the traumatic confrontation on Mustafar. Although the exiled Jedi still clung to his own master, his hold on his past was loosened, and Kenobi was able to focus and eventually succeed on his mission to watch over Luke, the son of Anakin Skywalker; by letting go of Mustafar and other past occurrences, Obi-Wan Kenobi was able to instruct the boy in the ways of the Jedi, guiding the young Skywalker as the latter went on to help restore balance to the Force and bring down Darth Sidious' empire.

Although Sidious had lost his original facility during the Clone Wars, he soon built additional installations on Mustafar where he continued to abduct Force-sensitive infants. Over time, he manipulated these children and molded them into members of the Inquisitorius, dark side agents trained by Darth Vader. Sidious stole the childhoods away from these individuals, turning them into hunters of the Jedi they may have otherwise become.

Vader's plans
Fascinated by the power he tapped into in the Sith cave on Mustafar, and associating the world with his rebirth and personal connection to the dark side, Vader requested that the world be given to him by his master around 14 BBY, believing that the planet held the key to seeing his deceased wife once again. Gifted with a Naboo starship, an ancient Sith mask, and a team of top Imperial architects, Vader departed Coruscant for his new home. The Sith Lord entered the planet's violent atmosphere unshielded, causing severe damage to his vessel and casting a streak of fire across the smokey sky. His entry was witnessed by the Mustafarian Father Kkkt, who warned his clanmate Zzzs that the fireball was an omen of events to come.

Landing near the Sith cave, Vader meditated within its dark walls, leaving the Emperor's architects, Colonel Alva Brenne and Lieutenant Roggo, to draw up plans for a personal base Vader could inhabit. Brenne scouted the terrain of the planet, believing that, although Vader was seemingly impossible to satisfy, she could manage to design a home suitable for the Dark Lord. Unbeknownst to the architects, the mask that Sidious had gifted Vader was possessed by the spirit of Darth Momin, a heretic artisan from the Sith's forgotten past. The mask took control of Roggo, using his body to kill Brenne and create its own designs for the base.

Vader confronted the spirit, killing its host body and demanding that it give him answers. The spirit introduced itself as Momin and offered to help Vader construct a fortress that would harness the energies of the dark side locus below the cave to open a door into the Force itself; through and beyond the limitations of time and space. After abducting the Mustafarian Sssp to serve as Momin's new body and taking command of a vast Imperial construction force on the Gahenn Plains, the two Sith Lords began their work on what would become Fortress Vader.

Portal to the past
The construction of the fortress was not a simple task. Over the course of eight attempts with at least five separate designs, Momin struggled to find the perfect structure that could correctly channel the dark side. The energy Vader exerted while attempting to open a rift in the locus caused electromagnetic storms to rage across the planet, throwing the world's creatures into a frenzy and casting the Mustafarian people into disarray. Father Kkkt, realizing the danger Vader posed to his world, rallied the clanholds across Mustafar prepared to mount an attack on the Imperial intruders.

Upon the completion of Momin's ninth design in 12 BBY, Vader was finally able to reach through the Force and open a pathway into time, but he was interrupted in his moment of triumph by Kkkt and his forces. With the Dark Lord distracted, Momin entered the portal and claimed his original body, betraying Vader. Kkkt's army had initial success in pushing back the Imperials, attacking them with surprise tactics. Vader, however, soon arrived and rallied the stormtroopers to double their efforts. Recognizing Vader as the Imperial leader, Kkkt lead the Mustafarians in powerful usage of the Force, drowning the enemy forces in a vast flood of lava. Vader was able to retreat into the fortress, summoning his own massive force of energy to destroy the Mustafarian attackers.

Returning to the inner sanctum, Vader confronted Momin, who mocked the cyborg Sith for his failures in service to the dark side. Using Momin's hubris against him, Vader crushed and killed the resurrected artist. With no one to stop him, he entered the portal, encountering visions of his past and future, including his beloved wife, Padmé. Upon witnessing what Skywalker had become, however, the vision of Amidala ran from Vader, choosing to kill itself. Frustrated with the dark visions clouding his attempts, Vader retreated and crushed the altar in the Sith cave, destroying the portal and accepting that the truth he encountered was exactly what he needed.

Mustafarian revolts
The Black Sun moved off of Mustafar to a lower-profile world after the Empire established a garrison there. Following Kkkt's failed attack and the completion of Fortress Vader, according to a story told years later by the Mustafarian Lellis, Darth Vader sought candidates for a servant who would attent to his needs, searching for months until the human named Vaneé came into his service. During Vader's search, an Imperial officer was sent from Imperial Command to Mustafar by Moff Seward, and tasked to handle an outbreak of insanity amongst Imperial Lava Troopers assigned to Fortress Vader. On Mustafar, the inspector found that the troopers had inhaled toxic fumes from the planet's depths that gave one illusions of fears and doubts, and thus entered Vader's castle to speak with Darth Vader himself with the intentions of resolving the matter. However, Vader, bathed in his bacta tank, instead forced the officer to inhale the fumes and confront his fears by holding him in place telekinetically, refusing to let the human go and stating that the fumes could be filtered later. Face with the illusions caused by the Mustafarian fumes, the inspector denied their existence and began to laugh, laughing for days until he took advice from the voices by his head and submitted to Vader as the servant named Vaneé.

Eventually, years before the Battle of Endor of 4 ABY, the lava fumes leaking into Vader's castle were blocked off. During the early days of Vader's reign over the planet, Vaneé witnessed the efforts of a second force of Mustafarians to push the Sith away from their homeworld. The group, led by Criakan, desired vengeance for their slaughtered kin and stormed the fortress in a surprise attack. Surrounding Vaneé, Criakan and his forces intended to show no mercy to the Imperials, but were shown the same respect by Lord Vader, who cut them all down before they could burn down the castle.

Sometime later, during a visit from the Emperor's adviser Rersey, a third attack on Fortress Vader was undertaken by Clan Rrrt's Mother Sssl, a Mustafarian priestess who could force her will upon others by subjecting them to a mind-altering plague. Sssl's forces soon overwhelmed the Imperials, infecting Vader's soldiers and turning them against the Sith. Although Sssl had only intended to scare off the invaders, her plans changed when the Dark Lord himself was seemingly infected. In reality, Vader's mechanical body was immune to the plague, allowing him to feign subservience and draw the priestess out. Using a mind trick, Vader forced Sssl to command her own forces to drag her into the lava, a sight that caused the adviser Rersey to lose his sanity. Vaneé praised his master and noted that the Mustafarians would fear Vader's name in the future.

Fire across the galaxy
Joining Vader on his new home, the Galactic Empire took control of Mustafar and maintained secret facilities on the world where Jedi survivors of Order 66 were interrogated and executed, though the lava planet was still only publicly notable for its mining operations. Rumor had it that Darth Vader carried out these interrogations, torturing the Jedi for any useful information before their execution. Additionally, both Vader and Sidious returned to the planet, using it as a focus for meditation on the power of the dark side of the Force. The latter half of the Imperial Era saw outsiders coming to Mustafar as conflicts arose against the rule of the Galactic Empire. With the establishment of Darth Vader's castle, both the Empire's leaders and rebels came to the planet as a result of the Imperial presence.

In around this time, the term "Mustafarian Special" was used by smuggler Lando Calrissian and his first mate, L3-37, to refer to a starfighter maneuver that involved great speed and surprise, and which ensured at least one side of a starship confrontation "end[ed] badly." L3-37 explained that the tactic was named such in reference to the eponymous lava planet's fiery nature.

Also around the time of Fortress Vader's construction, after being attacked by a trio of cadets when he was studying at the prestigious Royal Imperial Academy on Coruscant, the Chiss Mitth'raw'nuruodo recommended to the Imperial Academy's commandant, Deenlark, that his assailants should be transferred away. In response, Commandant Deenlark snorted with derision and asked if the Chiss wished to have the three attackers transferred to Mustafar as punishment. However, Mitth'raw'nuruodo suggested that the three train instead as starfighter pilots at the elite Skystrike Academy on Montross.

At some point prior to the Battle of Yavin, a smuggler and ZO-E3 were forcefully taken to Mustafar, taken out of hyperspace by an Interdictor-class Star Destroyer. While the duo was present, the smuggler was discovered to be a descendant of Lady Corvax, a ruler who once presided over Mustafar. As the smuggler and ZO-E3 made their escape, they attempted to retrieve the Bright Star to restore Mustafar to its former state. The smuggler briefly trained under Vader, learning of their Force sensitivity, though Vader later betrayed the smuggler, taking the Bright Star in an attempt to revive Padmé Amidala. The smuggler prevented this, staging an escape from Fortress Vader and destroying the Bright Star. This act allowed Mustafar to begin replenishing the ecosystem it lost long ago.

Galactic war on Mustafar
The strict travel restrictions imposed by the Empire made it difficult for the Mining Guild to make Mustafar profitable. While the world remained under heavy Imperial guard, mining operations on the planet eventually ceased. Four years before the Battle of Yavin, an Imperial fleet commanded by Grand Moff Wilhuff Tarkin aboard his personal Imperial I-class Star Destroyer, the Sovereign, orbited Mustafar. When the Spectres rebel cell leader and Jedi Kanan Jarrus was captured, he was brought aboard the Sovereign.

When the Spectres attempted a mission to rescue Jarrus under the leadership of Hera Syndulla, the Sovereign was destroyed during a duel between Jarrus and the Grand Inquisitor when the latter's lightsaber was cut in two by Jarrus and fell into the ship's power core, sending the vessel falling towards the lava fields below. With the aid of Phoenix Cell, a resistance group affiliated with a growing network of rebels formed by Senators Bail Organa and Mon Mothma, the Spectres successfully extracted their Jedi leader and joined the larger Phoenix Cell. The skirmish over Mustafar thus became one of the earliest rebel victories in the Galactic Civil War against the Empire.

Due to their Jedi members, and having become a part of Bail Organa's rebel network, the Spectres began to work with the former Jedi Ahsoka Tano on Jedi business. In around 4 BBY and 3 BBY, Tano reported to the Spectres' Kanan Jarrus that in her search for information regarding the Sith Lord—who, unbeknownst to the rebels, was Darth Vader, the former Anakin Skywalker and master of Ahsoka Tano—who attacked them over the planet Lothal shortly before, she had been monitoring transmissions from Mustafar, and despite information on the Sith Lord remained elusive, she had gathered more intelligence on the Empire's Inquisitors.

The former Jedi divulged her findings of that their secondary mission was to "make retrievals," along with two sets of coordinates she decoded from the Mustafar transmissions. Informed of the news, Kanan Jarrus and Ezra Bridger investigated one of the coordinates given to them by Ahsoka Tano. Together, they uncovered the Inquisitors' plot to kidnap Force-sensitive infants on Takobo, similar to Darth Sidious' attempt to take Jedi potentials to Mustafar for reconditioning that Tano, then former Padawan to Anakin Skywalker, foiled alongside her master during the Clone Wars.

Fortress of terror
Later in the war between the Empire and the Alliance to Restore the Republic, newly-formed from various rebel cells by Mon Mothma, a crew of rebels led by Commander Lina Graf was attacked by Imperial forces, and their ship, the Auric, was heavily damaged. They were forced to crash-land on Mustafar, a planet that Graf hoped would lead to her crew's salvation. Surrounded by lava, the rebels abandoned their ship and began toward the only structure in sight, Vader's fortress. They did not make it far before being attacked by Mustafar's exploding beetles. After defeating the beetles and arguing over the best course of action, Graf and her crew were cornered by a squad of Imperial Lava Troopers. Escaping the troopers, the group entered the fortress but soon became separated in its dark halls. Alerted to their presence by his aide Vaneé, Vader confronted the rebels, capturing Lieutenant Thom Hudd and destroying the bodyguard droid XM-G3, though Graf and her remaining crew managed to escape Mustafar. The rebels' successful escape from Vader's castle was remembered by the native Mustafarians by the aftermath of the Empire's collapse.

For the next several weeks, Vaneé kept Hudd locked within the fortress and tortured him, all the while tormenting him with horrific tales from across the galaxy, including the story of Vader's brutal murder of Sssl years prior. The abuse and starvation that Hudd suffered while chained to the Sith servant's torture web was so severe that he lost enough body mass to slip from his shackles and escape his cell. Hudd managed to send a distress signal to the Alliance but was ultimately recaptured and sentenced to death. His execution was stalled by Graf, however, who had returned to Mustafar disguised as an Inquisitor. Although Vaneé saw through her ruse, Graf and Hudd were able to escape and flee the planet with the rest of their crew. Vader, angered at his servant's ineptitude, rigged Vaneé up to the torture web, though he allowed him to live.

After gaining intel on the Empire's operations on the planet, a small Rebel force was sent by Captain Cassian Andor to infiltrate an Imperial base located near Vader's castle on the lava fields of Mustafar and steal a vital artifact to assist the Rebellion. Upon infiltrating the base, the Rebels discovered the artifact was a proto-saber, a precursor to the lightsaber. Despite the intervention of Darth Vader, the Rebels escaped with information about the ancient weapon.

Crushing aspirations
In 0 BBY, the Empire completed construction on the Death Star, an orbital battle station capable of destroying a planet. After a rebel attack on an Imperial laboratory on Eadu threatened to expose the Death Star's capabilities to the galaxy at large, Vader summoned the director of the project, Orson Krennic, to his fortress on Mustafar. Krennic, arriving while Vader was sustained within a bacta tank, was escorted into a rotunda in Fortress Vader by Vaneé to await the Dark Lord. Confronting the uneasy director, Vader admonished Krennic for his failures, using the Force to choke the aspirational officer when he requested an audience with Emperor. With his message relayed, Vader watched Krennic's ship depart for the planet Scarif.

Despite Vader's threats, Krennic would fail in his endeavors, and the Death Star was ultimately destroyed by the Rebel Alliance. Around the same time, the Rebels also destroyed the Empire's Mirkanite Mining Facility on Mustafar. Additionally, the loss of the Death Star served to galvanize resistance across the galaxy, causing trouble for the weakened Empire. In response to this outbreak of rebellion, Vader was met on Mustafar by Admiral Kendal Ozzel and General Maximilian Veers. Overlooking the planet's lava fields, the trio discussed the proper route to deal with the rising Alliance, though Vader viewed Ozzel's suggestions as nothing more than excuses for incompetency. An interesting point from General Veers, however, persuaded Vader to view the rebels in a new light, prompting him to develop a different plan to cripple the Alliance.

Into the fire
In 3 ABY, Vader attempted to turn his son, Luke Skywalker, to the dark side during a duel over the planet Bespin. After Skywalker fled, however, Vader temporarily abandoned his duties to the Emperor, embarking on a personal quest that led to the discovery of a rebel cell led by Sabé, the former decoy of Padmé Amidala. Vader allowed the rebels to live, a decision which convinced Sidious that his apprentice was in need of a reminder of his place. The Sith Emperor mutilated Vader on Coruscant, ripping his cybernetic limbs from his body and strangling him as he had done to men like Krennic in the past.

Not finished with his lesson, Sidious took his student back to Mustafar. He had Vader's personal guard of death troopers drag the crippled Sith to the spot where Kenobi had defeated him decades ago, leaving Vader to fend for himself. Warned by his master that there would be consequences should he use the Force to save himself, a one-armed Vader crawled along the lava banks and retrieved his fallen lightsaber before slowly making his way to the ruins of the Techno Union installation. Sidious watched from Vader's Lambda-class shuttle as the broken man pulled himself across the sand. Although Mas Amedda, the Emperor's Grand Vizier, warned that the Dark Lord planned to kill his master, Sidious was unconcerned and sent his Sith assassin, Ochi of Bestoon, to turn Vader's anger into pain.

Having reached the Techno Union installation ruins, the very building where he had slaughtered the Separatist Council decades prior, Vader repurposed surrounding Separatist droid parts as his own limbs and confronted Ochi, overpowering the assassin and demanding him to reveal Darth Sidious' plans. As Vader did so, the Eye of Webbish Bog called out to the Sith Lord, who, despite being deprived of his chest box and lightsaber by Ochi, fought his way through hordes of lava nymphs and lava fleas as well as a roggwart to reach the Eye's cavern. As Vader did so, he was tested by the Eye and reminded of his inner conflicts between his chosen Sith and Jedi destinies as well as between his personal desire of power and his need for his son. During Vader's journey to the Eye's lair, Sly Moore and a group of death troopers spoke to Ochi of Bestoon, reminding the assassin to abide by the Emperor's directives.

At the end of Vader's trek to the Eye, the latter gave the cyborg a wayfinder and allowed him to leave the cavern to rejoin Ochi. Once outside, Vader made his way to the green Jedi starfighter that he took to Mustafar at the end of the Clone Wars, repairing the ship until Ochi reappeared with the Droid Crush Pirates of Bestoon. Having been promised Vader's cybernetic parts by Ochi, the army of droid pursued the Emperor's enforcer until they found that his parts were no more special than their own. In the midst of a quarrel with Ochi about their deal, the droids were interrupted by Vader, who took down the machines for use in retrofitting his green starfighter and an escape pod, which he locked Ochi in after forcing the assassin to activate his wayfinder. In his determination to find the Emperor's secrets, Vader bound the pod to his starfighter and set off to the wayfinder's coordinates, reaching the vicinity of Exegol by way of hyperspace.

With Ochi in tow, Vader confronted Sidious on Exegol, an ancient Sith world which housed hundreds of Sidious' secret experiments and weapons. The Emperor reminded his wayward apprentice that he left him weak and broken on Mustafar's burning shores, and asked Vader what he learned from the experience. However, Vader remained rebellious, stating his intention to make his "master" fear him. Despite Vader's efforts, he was overwhelmed by Sidious' power. Terribly pained but having experienced a vision of his son telling him it was his destiny to destroy Sidious, Vader accepted his master's dominance over him for the time being before leaving Exegol with him and Ochi.

Ashes of Empire
Toward the end of the Galactic Civil War, Vader was saved by his son Luke Skywalker's selfless compassion and in turn sacrificed himself to destroy the Emperor aboard the second Death Star during the Battle of Endor in 4 ABY. Having re-embraced his identity as Anakin Skywalker as he succumbed to the injuries inflicted upon him by his late Sith Master, Vader died leaving his fortress without a host. After the battle, pilot Wedge Antilles went on a scouting mission to suspected Imperial planets. He reported back to the New Republic when he was on Raydonia before going missing above the planet Akiva. Due to its proximity to Raydonia, Admiral Gial Ackbar sent a scout to Mustafar, as well as to Tatooine, Dermos, and Geonosis, while two scouts were sent to Akiva.

Following news of Darth Vader's death over Endor that was broadcast by the Rebel Alliance, Mustafarians gathered around the fortress' vicinity in celebration of the fall of the Empire. Lightning storm clouds and lava on Mustafar stirred around Vader's castle, howls sounded in the night, and cries echoed across the lava plains. The Mustafarian boy Giggek recognized that his kind were not truly free as long as they lived under the shadow of Vader's castle, and so resolved to rid the land of Vader's curse by bringing the castle to ruin. Along with Tuttel, Giggek acquired detonators from a store of equipment from the obsidian mines belonging to Tuttel's uncle, Lellis. However, the latter forbid the young boys from entering Vader's castle for the reason that it was lethal and evil, telling the story of how Vaneé came into servitude under Vader and further speculating that the young Mustafarians were only wanting to be figures of legends.

Nevertheless, Giggek led Tuttel into Vader's castle by way of lava flea, venturing in to find a pit trapping Vaneé, the servant of Vader and the self-styled "one true Acolyte of the Beyond" who was detained by Vader there some time ago. Rescuing the Acolyte in hopes of not bringing death upon anyone in the process of destroying Vader's castle, Giggek was at once betrayed by Vaneé, who dropped the boy down the pit in hopes of bringing death to those who sought to tarnish his master's legacy. However, after instructing his Mustafarian companion to flee, which Tuttel did with their lava flea, Giggek ignited his explosives through a remote detonator, and although the blast did not bring down Vader's castle, Vaneé was buried in black sand. However, the Sith servant survived. A voice familiar to Vaneé told him not to fear, and assured its servant that he could return Vader to the fires of Mustafar and be made whole.

Mustafar grew in obscurity in the decades that followed, and Vader's castle eventually fell into ruins. Thanks to the destruction of the Bright Star, Mustafar's ecosystem began to be healed. Several individuals from off-world also visited the planet, including the spy Vi Moradi as well as the historian and adventurer Eloc Throno, who wrote of the world in Volcanic Planets: Your Guide to the Galaxy's Hottest Destinations, one of the many travel guides he wrote throughout his career. By 35 ABY, many pilgrims had come to the ruins of Vader's castle seeking to tap into the Sith Lord's dark power. One group of pilgrims, the Alazmec of Winsit, guarded the castle ruins as well as its secrets jealously, colonizing the nearby Corvax Fen—a rich soil ground—and planted a forest of irontrees in the hopes of restoring Mustafar's once lush landscape from centuries ago, believing that the soil was soaked by the tears of Lady Corvax.

Pathway to the Sith Eternal
After the destruction of the First Order's Starkiller Base and the Battle of Crait in 34 ABY, the Weequay pirate Hondo Ohnaka wrote about Mustafar in his book titled Galactic Explorer's Guide. During the ongoing war between the First Order and the Resistance in 35 ABY, First Order forces arrived at the planet via the Resurgent-class Star Destroyer Steadfast following a mysterious broadcast by the resurrected Darth Sidious. Knowing that Mustafar was once ruled by his grandfather, Darth Vader, Supreme Leader Kylo Ren regarded it as hallowed ground—the place where Anakin Skywalker died and a Dark Lord of the Sith was born.

Due to the wayfinder of Vader being located in the castle's ruins, the Supreme Leader and his stormtroopers attacked the cult of Alazmec colonists, who were sworn to protect the fen surrounding the ruins of Vader's castle. Having arrived at the planet in his TIE whisper, Ren slaughtered several cultists using his lightsaber in search of the wayfinder that would allow him to reach the planet Exegol in the Unknown Regions, where Sidious resided amongst his Sith Eternal followers, while General Armitage Hux and Allegiant General Enric Pryde observed Ren from afar.

After defeating the cultists, Ren traveled through the forest and arrived at a small lake, where he encountered a spider-like creature sitting atop a blind giant in the water. The spider creature, identifying itself as the Eye of Webbish Bog, informed Ren that it knew what he sought, but it warned him of encountering his "true self" if he were to continue down his current path. When Ren did not respond, the Eye relented and rewarded the Supreme Leader for his victory over the Alazmec, pointing the way to the Sith artifact. Ren was guided by wisps of the dark side and came to an altar surrounded by the ruins of Vader's fortress. Using the Force, he tore open the structure and finally discovered the wayfinder. The Eye of Webbish Bog and the giant then disappeared into the lake, leaving Ren alone with the artifact. Knowing that he would not be the only one to travel to Mustafar in search of the object, he and the rest of the First Order forces departed the planet.

Inhabitants
The Mustafarians
Mustafar was the homeworld of the Mustafarians, a species primarily concerned with their own advancement and survival that lived in underground caves created by the lava fleas that ate through the planet's crust. Two races of Mustafarians evolved in distinctly different cave systems in the mountains from extremophile arthropods, one subspecies living near the planet's equator and the other in the north. They lived together as needed, although the geographical distance and limited desirable living space tended to limit the subspecies in their own communities.

Only venturing up to the surface in order to collect valuable minerals from the lava flows, the southern Mustafarians carried out the heavy labor involved due to their short and strong physiology that developed due to the relatively higher gravity of their homeland, surviving high temperatures and frequent accidents on lava flows thanks to their thick carapaces, while the tall and slender northern Mustafarians had keen, faceted eyes which easily spotted flaws in ore and machinery alike, and who acted as guards and expert riders of the lava flea, a creature that the natives made their armor from the heat-resistant shells of.

Chitinous exoskeletons and low-water biology allowed Mustafarians to withstand the intense heat of their homeworld, though they still required insulated clothes and breathing apparatus to work on the surface. The native Mustafarians developed and sought technology for survival more so than most other species, and some enhanced themselves with cybernetics to better carry out common tasks and withstand the harsh environments of their homeworld. Having learned from tragic experiences, Mustafarians did not trust imported technology until they themselves modified and adapted them to Mustafar's climes. While the two Mustafarian subspecies lived together as needed, the geographical distance and limited desirable living space tended to keep them in their own communities, though it was not unheard of for clans to be comprised of both northern and southern Mustafarians.

The Mustafarians grew few crops, as the lack of water meant traditional farms, even when located underground, could not be sustained; water had to be imported to Mustafar. Nevertheless, despite the what little life Mustafar had compared to other worlds, various types of edible fungi and domesticated herds of large insectoid creatures made up much of the Mustafarian diet, and unlike other hotbeds of industry in the galaxy, Mustafar was largely self-sufficient in regards to its food supply. Southern Mustafarians made Mustafarian Lava Buns by placing sweet balls of dough upon the planet's volcanic crust, heating it up to create a red bread with a cracked and blackened exterior. The Artiodac chef Strono Tuggs witnessed the production of the baked goods during a visit to Mustafar, learning the recipe to the buns in the process. Tuggs later served the buns at his mobile restaurant on the Outer Rim planet Batuu after the fall of his previous place of employment on Takodana in 34 ABY.

Though they typically inhabited natural caverns and abandoned mines, Mustafarians built outdoor structures as necessary, including saucer-shaped buildings at and near active mining sites. Their structures were strongly reinforced and armored to protect them from natural disasters, making their larger facilities fortresslike in construction and durability.

The Mustafarian people shared a deep connection with their planet, seeking harmony with the natural forces that sculpted their homeworld. Surrounded by volcanic magma, their culture was tied to the ebbs and flows of the lava on which they lived. In the difficult times of the Empire, history and lore of Mustafar lived on in a Mustafarian leader known as the Priestess, who provided guidance and invaluable information to natives and visitors alike. The natives lived in clans, and members of Father Kkkt's clan spoke of "lifefires" and "endfires" while discussing the arrival of Darth Vader; Kkkt himself used the Force to form a symbol within a lava river, which he interpreted as an omen of the planet's future. The Mustafarians had a strong desire to protect their homeworld, banding together on multiple occasions to defend against Imperial forces. They had a special relationship with the other life on Mustafar; lava fleas were used to jump over lava flows in a rite of passage, and kahel cave fungi served as the inspiration for Mustafarian architecture. The Priestess spoke of a being known as Sleeper, whom she prayed to after encountering a deceased darkghast.

Mustafarians were politically organized in accordance with the caverns and communities they inhabited, though they had little in the way of a central government. However, some trusted leaders were allowed to make deals with offworlders in order to help ensure their survival and quality of life. As a result, the Mustafarians fell under the sway of the Techno Union and later the Mining Guild, serving them as ore scouts, miners, and refinery laborers. Though they resented the presence of offworlders, Mustafarians were generally willing to tolerate a degree of outside political influence as long as it furthered their own cause. Because of the demanding environment of their world, Mustafarians were generally insular and disinterested in galactic affairs, few regarding offworlders with much curiosity. Their focus on the advancement and survival of their own species overrode other concerns, a result of inhabiting a world that demanded so much in order to so much as continue living.

Mustafarians spoke a language of the same name, which allowed for the precise expression of concepts related to naturals features above and below ground, especially phenomena that were deceptively dangerous. Though the Mustafarian subspecies spoke different dialects, any two individuals could communicate on a functional level despite differing terms and cultural concepts. Though they were also capable of speaking Basic and other common galactic languages, most that did not work with the Mining Guild or deal with outsiders by necessity did not bother to learn Basic. However, Mustafarians that lived or traveled offworld almost always spoke Basic and sometimes the language of their trading partners. Due to their history with the Techno Union, they were more likely to know languages regularly used among former Separatist worlds.

Mustafarian travels off-world were driven by business pursuits and trade negotiations, and were generally restricted to the Outer Rim. So long as their safety or that of their companions was not threatened, the species was disinterested in galactic affairs, which made them foremost disinclined to leave their homeworld. For Mustafarian merchants and Mining Guild personnel, regular trips were made off-world to trade for upgrades in protective technology and equipment, as well as to deliver ores to buyers. However, there were some Mustafarians who sought full-time employment off-world. They found most inhabited worlds cold, yet relished the relative safety.

Invaders and colonizers
The Techno Union, a guild of technology firms led by Skakoans like Wat Tambor, came to value the lucrative minerals of Mustafar and set up operations on the planet. The offworlders introduced heavy industry, and were welcomed by the native Mustafarians in exchange for access to mining droids and heavy-duty speeders. However, the natives became subjugated, being put to work in the Techno Union's mining operations and charged rent on their own planet. Management staff of the Union utilized native buildings throughout their operations and provided a refuge for the Separatist Council during the final days of the Clone Wars.

Aside from the native people and the Techno Union, Mustafar was also inhabited by Falleen, tall and muscular repto-mammalians native to the Mid Rim planet of the same name that controlled the vast Black Sun criminal empire. Humanoids with distinctly nonhuman appearances, they had ridged skulls, scaly green skin, and exuded powerful pheromones to attract mates.

The Sith Lord Darth Vader called Mustafar his home during the Imperial Era. Originally coming to the planet in hopes of resurrecting his deceased wife, Vader lived on the volcanic world for over a decade, utilizing its scorched earth to conduct his personal business. Stories of the Jedi who died by his hand on Mustafar became synonymous with the planet itself. During his visit to Fortress Vader, Director Krennic theorized that Mustafar was Vader's homeworld, imagining that the Dark Lord's cybernetics were designed to allow him to survive while away from the molten planet. The Sith Lord's occupancy was known to others in the galaxy as well. After discovering that Mustafar was Vader's domain, the Naboo resistance group known as the Amidalans deduced that he was responsible for Padmé's death and plotted to kill the Dark Lord to avenge the fallen queen.

As Darth Vader established his personal headquarters on Mustafar, the forces of the Galactic Empire followed. The Imperials' occupation of the planet forced Black Sun and the Techno Union to abandon their operations, with the Mining Guild taking over what remained. Within both Vader's fortress as well as other installations, the Imperial Army had a sizable presence on the world, enough that the native population sought to remove them from the planet. Stormtroopers guarded Imperial interests on Mustafar; among their ranks were Lava Troopers, specialized soldiers that operated within the planet's volcanic environment. During this period, the agents of the Inquisitorius trained in their own fortress on the nearby moon Nur, keeping close to their master Vader and his castle.

Many groups of cultists came to Mustafar in the decades since Vader's passing, seeking the power that the Sith Lord once tapped into on the planet. One of these groups, called the Alazmec of Winsit, gained control of the Corvax Fen, a land of fertile soil. They planted several irontrees in the hopes of restoring the landscape that was once present centuries ago, and were devoted to guarding it from outsiders such as Kylo Ren and the First Order.

Other inhabitants
In the planet's vibrant past, the Mustafarians shared the world with Lady Corvax and her husband Dorwin, humanoids who lived peacefully with the natives. Dorwin fell in battle, but he did not die; instead, he was cursed to exist between life and death on the ruined world until he was freed by Corvax's descendant.

The ancient Sith established a presence on Mustafar, hoping to reap the benefits of the dark world and obtain immortality. At some point, the Sith Lord Momin found himself on Mustafar, and later, during the Imperial Era, recalled that long ago time.

Two mysterious beings resided within a small lake and guarded the path to the ruins of Vader's castle; one, a blind giant, and the other, an individual known as the Eye of Webbish Bog, were locked in a symbiotic relationship. Spoken of in the myths of the Mustafarians, the Eye was defended by the Alazmec of Winsit.

Locations
Settlements
The native Mustafarian populace, including both the Northern and Southern sub-species, took up residence in underground caves that were made by lava fleas munching through Mustafar's crust. Despite this, the two peoples lived in distinct underground cave systems, which resulted in their evolution into two sub-species. The Mustafarians' underground buildings were designed in the shape of kahel cave fungus, which was highly symbolic in Mustafarian culture.

Due to the planet's fiery surface, outdoor structures were built where necessary—usually at and near active mining sites—and buildings on Mustafar were held up by stem-like gravity supports. Its capital city was Fralideja, one of the few remaining Mustafarian settlements at the time of the Clone Wars. A cataclysmic eruption that occurred centuries before the war's end almost destroyed the entire local population. The city and its surrounding structures were of Mustafarian architecture: mushroom-like structures with a habitation dome raised from the scorched ground, based on the shape of the local culture's highly symbolic kahel cave fungus. The saucer-shaped structures were strongly reinforced and armored against natural calamities, with larger facilities on Mustafar becoming fortresslike in construction and durability. Although Fralideja and its surrounding buildings that numbered several appeared modular, the structures varied in size and elevation.

Another settlement was a mining town known as Zitontown, named for Ziton Moj, a senior Black Sun Vigo who rose to leadership of the organization during the Clone Wars. Located outside of town was as a fortified cliffside facility that served as the organization's headquarters during the conflict. The installation's architecture was distinct from other facilities located on Mustafar. Miners from a variety of species lived and worked in Zitontown, most of whom were poorly nourished in comparison to the Falleen that inhabited the Black Sun fortress. In addition to the fortress, Moj also possessed a palace.

Structures and installations

Darth Vader's Fortress on Mustafar
During the Clone Wars, Darth Sidious secretly maintained an old mining outpost. He planned to use it as a facility to train Force-sensitive children to become Dark Side spies. He tasked the bounty hunter Cad Bane with kidnapping children and delivering them to the facility for their training. However, it was destroyed in 21 BBY by Sidious' crew of nanny droids after Anakin Skywalker and Ahsoka Tano rescued multiple kidnapped children from the facility.

The Techno Union maintained multiple mining operations on Mustafar, including a complex built into a lava-filled mountain and a nearby residence for technicians and mine management staff located opposite to the capital city Fralideja. Around the area was a molten rock plain with erupting lava geysers that were repressed by the facility's repulsor fields. In addition to containing a secret command facility, the structure served as cover for a Techno Union droid production operation concealed inside the mountain upon which the mine sat, manufacturing battle droids for the Separatist Droid Army. The repulsor fields that protected the complex were inadvertently deactivated during the duel between Obi-Wan Kenobi and Darth Vader and the facility soon fell into ruin.

Fortress Vader was an obsidian tower built by the eponymous Sith Lord as a personal retreat during the Imperial Era. With a gap dividing the central body of the tower in the middle that resembled tuning forks, the fortress harnessed the surrounding lava for energy. It was also designed to channel the dark side's power, and, along with being near the site of the Sith Lord's duel against his former master Obi-Wan Kenobi, it was located above an ancient Sith cave to provide a more powerful locus of the dark side for Darth Vader to draw upon. When visiting the fortress, Imperial officers were intimidated by the surrounding environments, and the treacherous landscape of Mustafar worked to remind them of their place.

Other landmarks
Formerly a part of a Sith temple, the cave beneath Vader's castle contained a locus of the dark side of the Force. The walls of the cave were covered in glowing runic symbols, which Vader and Momin later rearranged to focus the energies of the planet. By tapping into the dark powers of the locus, an individual could open a rift between time and space to enter a portal through the Force. Darth Vader also forged his first red lightsaber at the cave, and Snoke, the First Order Supreme Leader who trained Kylo Ren, wore a ring that featured obsidian carved from the same cave.

The Corvax Fen was a vaguely hospitable bog that contained irontrees, being one of Mustafar's few such places. Located close to the ruins of Darth Vader's fortress, the fen was guarded by the Alazmec of Winsit, a group of cultists devoted to the Sith Lord. Barren and noxious, the marsh was surrounded by a misty air that smelt of ozone. It contained a shallow lake of brackish water that was covered in an oily film.

Places of Interest
Fralideja (capital city)
Fralideja was the capital city of the planet Mustafar.

Zitontown
Zitontown was a run-down mining town located on the planet Mustafar, precariously perched on a ledge overlooking a river of lava. The settlement contained a mining facility and ramshackle houses, which were towered over by a fortified compound that served as headquarters of the Black Sun syndicate during the Clone Wars. The town was named for Ziton Moj, a senior Black Sun Vigo who became leader of the organization during the conflict. The Last Resort was the only bar in Zitontown. A landing platform was located at the edge of the settlement.

Berken's Flow
Berken's Flow was a lavaflow that was a constant feature of the volcanic planet Mustafar. It was the largest lavaflow in the galaxy.

Black Sun fortress
The Black Sun fortress was a fortified compound built into a cliffside on the volcanic Outer Rim world of Mustafar. From within, a cabal of Falleen nobles led and operated the criminal syndicate known as the Black Sun during the Clone Wars. It was here that Maul and the Death Watch Mandalorians confronted the Black Sun leadership with an ultimatum to join the Shadow Collective, a criminal alliance set up and led by Maul.

Burning Plains
The Burning Plains was a region of the Outer Rim lava planet Mustafar which boasted heavy volcanic activity. The area was to the north of Mustafar's giant central volcano, and it was one of the few contant features of the planet.

Central volcano
The central volcano of the Outer Rim planet Mustafar was one of the lava world's few constant features. Lava poured out of the spot at nearly 100,000 litres per second and pooled at the giant volcano's base. Toward the north, heavy volcanic activity took place in the Burning Plains.

Crystal Flats
The Crystal Flats was a location on the planet Mustafar. It was made of solid rock, and in the Flats' north, minerals were naturally deposited in the crystalline there that the region's name originated from.

Darth Sidious's secret facility
Darth Sidious's secret facility was an outpost maintained by the Sith Lord Darth Sidious in a former mining complex located near a lava lake on the southern hemisphere of the planet Mustafar. During the Clone Wars, the bounty hunter Cad Bane delivered kidnapped Force-sensitive children there, where the Sith Lord planned to have them converted into dark side spies. The facility was destroyed by Sidious and his nanny droids when it was discovered by Anakin Skywalker and Ahsoka Tano, two Jedi on a mission to rescue the children.

Gahenn Plains
The Gahenn Plains were a location on the planet Mustafar. At some point during the reign of the Galactic Empire, the Sith Lord Darth Vader had his castle built over the ancient Sith cave located in the Gahenn Plains.

Corvax Fen
Corvax Fen was a forested area on the planet of Mustafar. It had become home to a cult called the Alazmec of Winsit, which became dedicated to restoring Mustafar to a thriving state and were ultimately guarding the ruins of Darth Vader's castle. The Alazmec cultists believed that the soil of the fen was fertile having been soaked by the tears of Lady Corvax, and devoted themselves to protecting and reinvigorating the grove by planting a forest of irontrees. In 35 ABY, during the First Order/Resistance War, Kylo Ren arrived with a group of First Order stormtroopers, massacring the Alazmec cultists and stealing a Sith wayfinder that had once belonged to Vader.

Corvax Fen developed after Lady Corvax's descendant destroyed the Bright Star during the battle on Mustafar decades before. The destruction of the Bright Star unleashed its energy upon the planet's desolate soil, eventually developing the forest.

Corvax Fortress
The Corvax Fortress, also known as Lady Corvax's sanctum, was an ancient castle once owned by Lady Corvax and located on the planet Mustafar. It was located beneath Fortress Vader, and was believed by ZO-E3 to be pre-Galactic Republic.

Fortress Vader
Fortress Vader, also known as Darth Vader's castle and Vader's personal abode, was a stronghold located on the volcanic world of Mustafar. Once the site of a Sith temple, the fortress was built above a Sith cave that still remained. Existing by the time of reign of the Galactic Empire, the Sith Cave contained a dark side locus.

The castle was designed by the preserved consciousness of the ancient Sith Lord and artist Darth Momin, whose haunted mask possessed an Imperial lieutenant and made him create the fortress's blueprints. Momin meant for it to channel the Force energies from the dark side locus under the castle and open the door to the dark side. The Sith Lord Darth Vader allowed Momin's design to be built using Imperial resources in his possession. Although Vader failed to open the door with the first design, after a trial and error process involving seven more designs, a perfect design was finally built. It was able to open the door to the dark side, but when Vader was distracted by a Mustafarian uprising, Momin opened it for himself and resurrected his original body.

Despite Vader's intervention, the army of Mustafarians were able to wipe out the Imperial garrison. Vader retreated to the castle and used its power to do the same to the Mustafarians. Momin then confronted Vader and was able to badly damage Vader in their brief duel. Vader crushed him using a stone slab. With Momin, the Mustafarians, and the Imperial garrison dead, Vader was left alone to open the door to the dark side himself. Vader's spirit entered the portal in search of his dead wife, Padmé Amidala. He returned unsuccessful and used the fortress' power to destroy the portal. He then contacted his master, Emperor Palpatine, to confirm his planned return to Coruscant.

The castle came to serve as Vader's personal residence and from time to time, he rested inside a bacta tank. On one occasion, his stasis was cut short by Director Orson Krennic of the Death Star project. The two discussed the project at hand. Vader also conversed with Admiral Kendal Ozzel and General Maximilian Veers there about the over stretching efforts to defeat the Rebel Alliance.

Details
Fortress Vader was a castle designed by the Sith Lord Darth Momin and occupied by the Sith Lord Darth Vader. Momin intended for it to tune the Force energies from the dark side locus under it and open the door to the dark side of the Force. It was constructed by Vader himself as a testament to his own might, with the assistance of his Imperial resources. It was located on the site of his greatest defeat, and was built over an ancient Sith cave in the Gahenn Plains. The complex's location and design came as much from the dark side of the Force as it did Vader's personal history. The central tower was constructed out of obsidian, and its tuning towers served as conduits for the dark side. Within, Vader maintained a bacta tank where he would remove his armor and rest inside.

History
In 12 BBY, two years after a rogue Inquisitor chase, which Darth Vader successfully dealt with, Vader's master, Emperor Palpatine, rewarded him by offering Vader a chance to build a base on any planet of his choosing. Vader chose to live in the unforgiving environment of the volcanic planet of Mustafar, as it was highly linked to his connection with the dark side. Palpatine accepted and sent Vader to the planet, accompanied by the Imperial colonel Alva Brenne and Lieutenant Roggo, as well as the Mask of Darth Momin, which Palpatine had found in a hidden room in the Jedi Archives years prior and had already communicated with. Upon arrival, Vader scouted the area and decided to have the fortress to be built over an ancient Sith cave, which Vader had meditated in before. Vader returned to meditate in the cave, but was interrupted by Brenne, who had created a design for the fortress. Vader rejected it, and Brenne returned to the ship.

Upon her return, Momin's mask killed Colonel Brenne and possessed Lt. Roggo, finally giving Momin a corporeal form after many centuries. During his possession of Roggo, Momin created the first blueprints for the fortress, designing it in such a way to maximize its attunement to the Dark Side.. Momin then showed these blueprints to Vader upon his return. Vader killed the possessed Roggo and took Momin's mask into the Sith cave, where the mask gave Vader a vision of Momin's past and his love for art, and then attempted to possess Vader, though Vader resisted. Shortly after, a group of Mustafarians attacked, and the mask possessed one of them. In his new body, Momin stated that the design he had for the fortress would act as a tuning fork for the Force, and promised Vader that if it was constructed, Vader would finally be able to achieve a way to meet his lost love again. Vader threatened Momin, stating that Palpatine had already lied about this to him prior and that Momin would be killed if he did not live up to his word.

Construction began for Momin's design. With the aid of Vader's countless Imperial resources, the fortress was soon finished. Vader attempted to use it in opening the door to the dark side, but it failed and the fortress was wrecked. The pair retried with four more of Momin's designs, but they also failed. Every time Vader tried to open the door to the dark side it affected the rest of Mustafar, causing lava storms all over the planet to wreak havoc on the Mustafarians. Lava fleas began swarming the construction site regularly because of this. After the failure of Momin's fifth design, Vader killed the body his spirit possessed as a punishment and had his mask possess a stormtrooper. Following the failure of Momin's sixth design, Vader killed his newer body and had the helmet possess an Imperial officer. Momin had confidence in the seventh design. But it failed as well, and Vader replaced his body with a Lava flea's.

When Momin's eighth design failed, Vader once again killed his body and had the mask possess an Imperial construction worker. This time, Vader told Momin there would not be another chance. Momin had great faith in the ninth design. Vader began to channel the force from the Sith Cave and the pair saw it was working. However, Captain Junus, the commander of the fortress' garrison alerted Vader of another attack, one the Imperial forces could not defend against. Vader left the Sith cave to deal with this while Momin double crossed him, opening the door to the dark side himself and resurrecting his original body. As his mask greeted it, the possessed body of the Imperial construction worker handed over the mask and Momin was made one again.

The Imperial garrison attempted to flee when Vader intervened and turned the tide of the battle. From afar, the Mustafarian leader Kkkt and his fellow chieftains then used the Force to bring a flow of lava onto the Imperial forces. The battlefield was wiped clean, and only Vader survived. Kkkt brought his remaining forces to attack the fortress and Vader entered the Sith cave. From there, he channeled the Force through the tower and caused a lava storm to wipe out Kkkt and his army.

Momin appeared from behind and confronted Vader. Momin claimed that Vader was weak, that he ought to serve the dark side, rather than seek to control it, and that Vader would never be able to open the portal as the dark side would have rejected him. The two dueled for a time, while Momin lamented the apparent regression and dilution of the power of the Sith in the millennia since his death, calling them weak and "Jedi-obsessed." Vader, who had been damaged during the battle and had expended a considerable amount of energy destroying the Mustafarians, received several devastating wounds from Momin during their duel. Unrelenting, Vader reached out with the Force and crushed Momin beneath an enormous stone. Momin proclaimed that he would not die, for the dark side loved him, and Vader replied that if that was indeed the case, then he would be saved by the will of the dark side. However, Momin could not summon enough power to overcome Vader's, and Vader slammed the stone flat against the wall, killing the disbelieving Sith Lord. Vader proclaimed his destiny was his own, before opening the portal himself.

Vader's spirit left his body and entered the portal, in search of his beloved Padmé Amidala. During his search on the other side, Vader's spirit came across a vision of his fortress and its many former designs before it turned into the Jedi Temple. Vader's spirit soon returned, unsuccessful of his objective, and merged with his body again. After this, he used the fortress to once again tune the energies of the dark side locus and destroy the portal for good. After this, he contacted Palpatine, saying he was ready to return to Coruscant.

Not long after its completion, a large horde of Mustafarians launched a raid on the fortress. The Mustafarians, led by Criakan who rode upon a Lava flea, entered through the fortress' hanger and quickly over took the fortess' Lava Troopers. As they descended deeper into the fortress, the Mustafarians came upon Vaneé and quickly surrounded him. Vaneé started to speak of mercy when Criakan took him by his robes and asked why they should show him mercy when his master did not as he slaughtered their kin. However, Vaneé quickly pointed out that he was not speaking to them as Darth Vader appeared behind them with his lightsaber drawn. Vader procceded to kill the Mustafarians.

In 5 BBY, the Jedi fugitive Kanan Jarrus had heard rumors about Mustafar, specifically referring to it as a place where Jedi survivors were sent to die if captured by the Galactic Empire. Before Jarrus could be taken to the surface, however, he was rescued from the Star Destroyer Sovereign in orbit by his fellow rebels.

Circa 1 BBY, members of the Rebel Alliance conducted a mission to infiltrate an Imperial base near the castle for Captain Cassian Andor. Disguised in stormtrooper armor the four traveled to Mustafar with their pilot Athex and the reprogrammed security droid K-2SO in a stolen Imperial transport. Upon arriving, the Imperial base was not happy to hear of the ship's arrival and demanded the ship land immediately and be ready for inspection. A hover platform docked with the ship and took the spies across to the main base, before taking a lift down to the base. They found a rack of blasters inside and the alarms started going off. K-2SO informed the others of this and instructed them to pick up the blasters and find their target. As the base responded to the threat, Stormtroopers filed out onto walkways to try and shoot the rebels. They were ultimately defeated, but and insectoids rose from the lava and spat fire at the infiltrators. A giant insectoid backed them until the spies killed it as well.

K-2SO unlocked the door for the rebels to enter inside the base. As the rebels moved back into a corridor, K-2SO presented them with a memory puzzle whilst Stormtroopers were shooting the rebels from behind. They then ran down another corridor leading to a room containing the weapons crate the rebels were dispatched to get. Athex opened the crate and found a proto-saber. However, Darth Vader arrived and threw his lightsaber at them, stabbing Athex in the chest. The infiltrators fired at Vader and the Stormtroopers that arrived to reinforce him. Vader used the Force to crush their weapons and began walking towards the party. K-2SO then rammed the Imperial transport into the side of the building, scooping up the spies and the crate. After leaving atmosphere, they jumped to hyperspace.

At some point, the Auric, a Rebel YT-1760 Small Transport serving under Commander Lina Graf and her crew, was shot down by TIEs above Mustafar and crash-landed near the castle. After barely escaping the ship as it sunk into the lava, Graf decided to go to the fortress in order to find a way off the planet, much to the protest of Lieutenant Thom Hudd. After removing their Rebel insignias and rank pins, she and her crew traveled to the castle, but were confronted by the Castle's Lava Troopers, which shot at them.

Graf and her crew were able escape the lava troopers while XM-G3 kept them busy and reached an entrance into the castle. Hudd sliced the door open and they walked inside. CR-8R questioned the structure while the technician Skritt feared there was a trap waiting for them. Graf knew of a base on the other side of the fortress and assured them they would be getting out. To calm Skritt's nerves, she told him a story about the Emerald Witch. G3 returned to them, having defeated the lava troopers, and Hudd decided to try and steal something and found an artifact in one of the rooms.

Suddenly the rest of the crew heard him scream and ran to where he had gone, only to find no trace of him. They split up in search of Hudd and G3 went off with Skritt, telling him a story about the Gorax along the way. They found the castle's attendant, Vaneé, in the control room. Vaneé was reporting their presence to Vader when G3 confronted him. After telling Vader they had found him, he watched as the Dark Lord of the Sith arrived and ripped G3 apart in front of Skritt. Skritt reported this to Graf, and she left 8R, only for him to be attacked by Vader straight after.

Graf and Skritt ran down a hall way where they came under attack by security droids under Vaneé and Lord Vader. Graf tried to shoot Vader, but he was able to withstand and deflect her shots. After Vader tossed Crater at Graf, she and Skritt made their escape to the castle's hangar. There, a Mustafar beetle attacked the lava troopers, while Graff and Skritt were able to steal TIE fighter and escape.

In 0 BBY, Vader was meditating inside the bacta tank in his sanctum when Director Orson Krennic arrived. Sending Vader's assistant Vaneé to retrieve him, Krennic and Vader discussed the Death Star. Krennic wanted more credit for the project but Vader refused to help him. When he asked if he still had command, Krennic was Force choked by the Sith Lord as a warning. After the meeting, Vaneé told Krennic to keep all that he saw of the castle to himself.

Following the War on Shu-Torun, Vader met with Admiral Kendal Ozzel and General Maximilian Veers to discuss the Empire's construction projects that had been delayed due to the Death Star's destruction. Ozzel and Veers stood behind Vader as the Dark Lord looked out the window of the chamber. Vader spent the majority of the meeting looking out over the Mustafar landscape. He asked for Ozzel to report on the growing rebel nuisance in the galaxy. Ozzel tried to explain the difficulty in destroying them and suggested mobilizing Vader's new Death Squadron. Veers then claimed the difficulty in destroying them was the fact they were always spread out, suggesting that catching them together may prove more of a blow. Vader acknowledged this and devised a plan to hit a blow to the rebellion.

Legacy
Following the death of Vader, the fortress was left in ruins and vacant. Its grounds eventually came to be protected by the Alazmec of Winsit, a Sith cult who colonized Mustafar and protected Corvax Fen.

At some point, Snoke acquired a black obsidian stone from the catacombs beneath the castle, which he used to make a ring for himself.

In 35 ABY, the Alazmec colonists guarded the Sith wayfinder at the fortress ruins in Corvax Fen. The colonists were ultimately cut down by Supreme Leader Kylo Ren of the First Order and his stormtroopers, who had traveled to Mustafar to collect Vader's wayfinder that led to Exegol.

Imperial base (Mustafar)
In between 2 BBY and 0 BBY, members of the Rebel Alliance undertook a mission to an Imperial base located near Fortress Vader on Mustafar. During the mission, Alliance members infiltrated the base and discovered a proto-saber.

Sith cave
An ancient Sith cave located deep beneath the surface of the volcanic Outer Rim Territories planet Mustafar served as a locus for the dark side of the Force. Built by the ancient Sith as a Sith shrine to seek the secrets of eternal life, the cave resided in the course of one of the planet's lava rivers on the site of a former Sith temple in the Gahenn Plains, and was strong with dark side energies.

Shortly after the rise of the Galactic Empire, the newly-christened Sith Lord Darth Vader traveled to the Sith cave to use its energy to bleed a kyber crystal in the construction of his own lightsaber. Vader later decided to build a fortress over the cave that could channel the power of the dark side in order to resurrect his deceased wife, Padmé Amidala. Using designs obtained from the ancient Sith Lord Darth Momin, whose spirit was trapped within an artifact, Vader constructed a massive obsidian castle over the cave that would serve as his personal residence.

The castle's construction caused natural disasters across the planet, prompting the native Mustafarians to launch an attack on Vader. Although the attack failed, it gave Momin's spirit the opportunity to open a portal through the Force inside the Sith cave and summon his physical body while Vader was distracted with the Mustafarians. However, Momin's resurrection proved short-lived, as Vader killed the ancient Sith Lord and passed through the portal himself. Even though he was unable to save Amidala, the visions Vader experienced throughout his journey into the portal allowed him to accept his fate.

An ancient Sith cave was located among the Gahenn Plains on the volcanic Outer Rim Territories planet of Mustafar and served as a locus for the dark side of the Force. Situated deep beneath Mustafar's fiery surface and housing a Sith shrine, the cave resided in the course of a river of lava, which flowed through and dropped out of the cave as a lava fall. The cave's interior featured various markings on its walls, as well as a round rock table formed at its center.

History
The Sith cave resided on the site of a former Sith temple, as well as an ancient castle owned by Lady Corvax, a powerful Force-user obsessed with immortality long before the reign of the Galactic Republic. Corvax's quest eventually led to the devastation of Mustafar, turning the planet into a volcanic wasteland. The legends about Corvax's story later led the ancient Sith to the ruined world, who erected the Sith shrine in order to seek the same secrets of eternal life.

Shortly after the formation of the Galactic Empire in the year 19 BBY, the Sith Lord Darth Sidious ordered his newly-christened apprentice, Darth Vader, to steal a Jedi's lightsaber in order to construct one of his own. After obtaining Jedi Master Kirak Infil'a's lightsaber, Vader, again following his Master's orders, traveled to Mustafar, where he had previously suffered severe burns all over his body as a result of his lightsaber duel against his old Jedi Master, Obi-Wan Kenobi.

To complete the task of constructing his new lightsaber, Vader needed to draw upon the Sith cave's dark energy and bleed the stolen lightsaber's green kyber crystal, which entailed corrupting the crystal with the power of the dark side and turning its color to red in the process. After Vader placed the crystal on the cave's rock table, the markings on the walls began to glow as he experienced a Force vision in which he denounced the dark side, killed Darth Sidious, and returned to Kenobi's side. By re-embracing the darkness, Vader escaped the vision and finally bled the kyber crystal.

Impressed by the Sith cave's dark power and the possibilities that came with it, Vader later decided to build his own fortress over the dark side locus and make Mustafar his stronghold. The Sith Lord's request was approved by Sidious, who speculated that Vader would perhaps be able to resurrect his deceased wife, Padmé Amidala, by using the dark side energies there. Believing that it could prove useful for Vader's quest, the Sith Master also told his apprentice to take the ancient mask that once belonged to the Sith sculptor Darth Momin, who went against the Sith's legacy of destruction and instead preferred to create artworks that would evoke pain and fear in viewers. The ancient Sith artifact also contained Momin's spirit, trapped inside for many years.

Vader traveled to Mustafar aboard his late wife's royal starship and was accompanied by Chief Imperial Architect Alva Brenne along with her assistant, Roggo. While Vader was meditating alone inside the cave, Roggo became possessed by Momin's mask and killed Brenne. When Vader returned to the starship parked near the cave's entrance, he found Roggo working on the fortress's design while wearing the ancient mask. The Sith Lord then killed the possessed assistant with his lightsaber and retrieved the hologram of the early design.

Vader subsequently took the mask with him inside the cave and used the Force to activate it. While the mask's eyes glowed red, Momin's trapped spirit told Vader his story—his sculpting philosophy that he adopted as a youngling, how he was trained in the ways of the dark side by Sith Lady Darth Shaa, and his ultimate defeat by the Jedi before he could complete his "masterpiece." By doing so, the spirit made Vader unconsciously wear Momin's mask instead of Vader's own helmet. Taking off the mask immediately when he came to himself, Vader found an alternate host for Momin by attacking a nearby Mustafarian patrol, capturing a Northern Mustafarian named Sssp, and forcing the captive to wear the mask.

Vader and the possessed Mustafarian soon returned to the Sith cave, as Momin suggested that his design for the fortress would finally allow him to create the "masterpiece" that he had always wished to build, and that it would also be the key to unlocking the locus's dark power capable of resurrecting Vader's wife and breaking the boundary between life and death. Vader choked the possessed Mustafarian with the Force as a warning against betrayal but nevertheless allowed Momin to proceed with his design.

An Imperial construction site was soon established around the Sith cave. Imperial magma troopers, AT-ACT and AT-ST walkers, and TIE fighters protected the area against lava fleas, which had been attacking the site since the first construction attempt—a magma trooper speculated it was because the location served as the creatures' breeding ground. After eight failed designs, each of which caused powerful lightning storms and lava overflows across the planet that destroyed the construction, the castle was finally completed by 12 BBY.

In the final design, several rectangular, inclined stones were placed around the table at the center of the cave, which served as the focusing chamber for the local dark side energies. The massive obsidian tower, designed to channel the power of the dark side, was divided in the middle to resemble tuning forks, and it harnessed Mustafar's lava for energy.

Positioned in front of the table inside the cave, Vader used the Force to activate the castle, and a burst of light in various shapes shot from the top of the tower and up through the sky. Although he successfully opened a portal through the Force, Vader's effort was interrupted by Captain Junus, commander of the castle's Imperial garrison, who reported to the Sith Lord via comm that they were under assault by a large army of Mustafarians. When Vader left the cave to inquire about the situation, Momin activated the castle and used its power to provoke a lightning strike on Vader outside. Momin soon opened the portal for himself and summoned his physical body, which reclaimed his mask from its possessed host.

Upon noticing that Vader had joined the battle, Father Kkkt and two other Force-sensitive Mustafarians combined their strength to flood the battlefield with lava, killing both Imperial and Mustafarian combatants alike. As the sole Imperial survivor, Vader retreated to the castle while the remaining natives launched their final attack to destroy the dark fortress. Back inside the Sith cave, the Sith Lord activated the castle in order to erupt the lava in the area surrounding the fortress, which decimated the rest of the Mustafarian army.

Momin subsequently revealed his resurrection to Vader, and the two Sith engaged in a lightsaber duel inside the cave. Although Momin claimed that the dark side would never allow Vader to reach the other side of the portal and seemingly held the advantage after cutting Vader's lightsaber hand, Vader eventually overpowered and killed Momin by smashing him against the wall with one of the rectangular stones around the table. Having defeated all his enemies, Vader finally reopened the portal to resurrect Amidala.

While his body was left behind inside the cave, Vader's consciousness passed through the gateway. Inside, Vader faced various figures and events from his past, and he also experienced brief visions of the future, such as his confrontation with his former Jedi Padawan, Ahsoka Tano, at the Sith temple on the planet Malachor. Although he eventually reached a vision of his wife, he was not able to save her, as the apparition rejected him by claiming that Anakin Skywalker, Vader's former self, was dead.

Vader's vision was ultimately interrupted by the appearance of a distant figure wielding a blue lightsaber—Vader's son, Luke Skywalker, whose existence was unknown to the Sith Lord. As Vader regained his consciousness, he destroyed the gateway by stabbing the rock table with his lightsaber. The portal's destruction caused the lower ground in front of the castle to collapse, revealing the buried castle that once served Lady Corvax.

Decades later, the First Order's Supreme Leader Snoke wore a ring with obsidian carved from the Sith cave. The golden ring was also etched with glyphs of the Dwartii. Also around that time, Luke Skywalker, who had become the last Jedi Master in existence, included a mention of ancient cave in a book where he chronicled the history of the Jedi Order, titled The Secrets of the Jedi.

Sith temple (Mustafar)
A Sith temple was located in the Gahenn Plains of the planet Mustafar, constructed over a cave that housed a locus of the dark side of the Force. Though gone by the time of the Clone Wars, the temple's existence was well-known by the Sith Lord Darth Sidious, who maintained a secret facility on the planet. Fortress Vader, the personal abode of his apprentice, Darth Vader, was built on the site of the former temple.

The Last Resort
The Last Resort was a bar on the planet Mustafar during the Clone Wars. Asajj Ventress and Quinlan Vos, who was operating undercover, traveled to The Last Resort when they were hired to retrieve Pyke Syndicate boss Marg Krim's family, who were being held hostage on Mustafar by Black Sun.

Mensix Mining Facility
The Mensix Mining Facility was a mining facility located on the planet Mustafar.

Mustafar droid factory
A secret Techno Union droid factory was concealed inside a mountain on the planet Mustafar, its existence covered up by a Techno Union mining facility located on the same mountain. During the Clone Wars, the Confederacy of Independent Systems manufactured armies of battle droids using the droid production operation.

Mustafarian Mining Complex
The Mustafarian Mining Complex, also known as the Mustafar mining facility or the Separatist stronghold, was an ore collection complex located on the planet Mustafar.

Valuable ores were mined from the lava and are extracted in different ways. The facility used electromagnetic extraction technologies as well as manual Mustafarian and droid extraction. Owned by the Techno Union, the mining facility was used as cover for the battle droid factory concealed inside the mountain upon which the mine sat. A secret command center was built onto the mining complex to serve as a final redoubt for the Separatist Council.

History
Shortly before the Battle of Utapau, General Grievous was instructed to send the Separatist Council to the mining complex for their safety. Little did they know, Darth Sidious was sending the council there so they could be easily disposed of later. There, the council was slain by Darth Vader, a Sith Lord, ending the Clone Wars. Shortly after, the complex was the site of a duel between Vader and Jedi Master Obi-Wan Kenobi. The wanton damage of their confrontation compromised the system controlling the protective repulsor fields that kept the facility from melting in Mustafar's extreme heat and most of the complex was consumed by volcanic eruptions.

Sometime between 3 ABY and 4 ABY, Darth Vader had a flashback of Padmé Amidala being Force choked around this area while being Force-choked by Darth Sidious. After Palpatine left him on Mustafar without his left arm and either of his legs, Vader crawled into the complex. He had flashbacks of his mission to kill the Separatist Council. There, with the help of mouse droids, he replaced his missing limbs with spare parts. Ochi of Bestoon arrived to kill Vader, and the pair dueled fiercely.

Smoking Forest
The Smoking Forest was an area on the Outer Rim lava planet Mustafar. One of the planet's few constant features, the region was named for the tree-like, smoke-belching rock chimneys there.

Tulrus Island
Tulrus Island was a landmass surrounded by tall mountains on the volcanic planet Mustafar.

Ziton's palace
Ziton's palace was a palace on Mustafar affiliated with the Black Sun Vigo Ziton Moj. The palace had a courtyard, a tower and was heavily guarded. During the Clone Wars, the Black Sun took Tezzka Krim, the wife of Pyke Syndicate head Marg Krim, hostage and imprisoned her at the palace until she was rescued by Asajj Ventress and Quinlan Vos.