Darth Momin

Darth Momin, also known simply as Momin, was a humanoid male Sith Lord, dark side scholar and sculptor. At a young age, his artwork led to his imprisonment by those who found it disturbing and repulsive for the very materials he had employed. The Sith Lady Darth Shaa freed him, claimed Momin as her apprentice, and trained him in the dark side of the Force. However, feeling he was second to none and that calling oneself "Master" was anathema to the dark side, Momin killed Shaa and began exploring its lore on his own. He eventually designed weapons like the Fermata Cage and a superweapon capable of destroying an entire city, but his deepest desire was to freeze people in time during their moment of terror. As the Jedi intervened during Momin's attempt, he lost control of the energy he wielded and his physical body was destroyed, leaving only his mask with his consciousness inside.

Many years later, Darth Sidious recovered Momin's mask from the Jedi Archive vault. After learning of Momin's story from the mask, Sidious gave it to his Sith apprentice Darth Vader as a gift for his journey to Mustafar, which Vader sought to make his personal stronghold. There, the mask possessed one of the officers and began designing a fortress. After Vader killed the host body and examined the mask, it told him of Momin's past. Vader then allowed it to possess a Mustafarian and grant Momin's consciousness a new physical form. Vader discussed the fortress Momin had designed, and soon permitted its construction.

Momin, with the help of Imperial resources supplied by Vader and a succession of host bodies, began designing a fortress that could tune the energies of the dark side locus on Mustafar and open the door to the dark side of the Force. While Momin's fortresses were repeatedly destroyed by the harsh natural conditions on the planet, the ninth design was successful. Shortly after the fortress was finished, whilst Vader was distracted by an invasion of Mustafarians, Momin undermined him and opened the door to the dark side. He used it to resurrect his physical body. Vader soon returned to the fortress and used it to obliterate the Mustafarian attackers. Momin then confronted him and, after a short duel, Vader used the Force to ram him with a stone slab. Momin was crushed against the wall and died.

Years later, Momin's mask was on Darth Sidious's personal yacht, the Imperialis. During the ship's infiltration, the mask corrupted two infiltrators, forcing the others to abandon and destroy the Imperialis. Momin's death at the hands of Vader created a Force nexus in the cave, thus creating visions that could haunt people. Sometime in between 3 and 4 ABY, the Knights of Ren encountered a vision of Momin at Fortress Vader.

Text and facts from the “Darth Momin” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.