During the Clone Wars, the leaders of Black Sun oversaw their crime syndicate’s operations from a fortress on the lava world Mustafar – a stronghold that was attacked by Darth Maul and his fledgling Shadow Collective.

At the conclusion of the Clone Wars, Anakin Skywalker killed the members of the Separatist Council, who had taken refuge on Mustafar. Padmé Amidala and Obi-Wan Kenobi followed Anakin to the planet, and Anakin and Obi-Wan dueled with their lightsabers.

The duel ended with Anakin near death, but he was found by Darth Sidious. The Sith Lord left Mustafar with his gravely injured apprentice, who would rise again as the black-armored Imperial enforcer Darth Vader.

Under the Empire, Mustafar remained an obscure world notable only for its lava mining. But the Empire used secret facilities on the hellish planet for the interrogation and execution of captured Jedi exiles. Kanan Jarrus was interrogated on a Star Destroyer orbiting Mustafar.

While Darth Vader suffered a terrible defeat on Mustafar, he would choose to make the lava planet his home. The Sith Lord constructed a massive castle, harnassing Mustafar lava for energy. The building was a blackened tower, dividing in the middle to resemble tuning forks. According to legend, it was built on the site of an ancient Sith cave, and the tower itself was designed to channel the power of the dark side.

After the fall of the Empire, the ruins of Vader’s castle became a pilgrimage site, jealously guarded by cultists devoted to the dark side. As Kylo Ren discovered, these devotees were protecting secrets that had once been Vader’s.