momin was an artist, architect, and anarchic sith lord from 1000 - 1100 BBY whose existence was all but erased from sith history for his heretical views on the force, and his belief that sith knowledge should be passed down and preserved rather than hoarded. momin believed that the sith aren't controllers of the dark side, but were, rather, controlled and moved by it akin to an artist controlled by their muse. after killing his master darth shaa and rebuking the rule of two and the sith traditions of his time, momin dedicated his life to creating artwork venerating and worshipping the dark side, his "Dark Mistress", culminating in his magnum opus: a death engine so powerful it time-locked a mustafarian city on the verge of annihilation, all their fearful souls screaming in terrible harmony for eternity. an engine mishap caused an explosion. his sculpture was destroyed by jedi, but it taught him new mastery of the Dark Side and the ability to trap his soul in time, making his spirit immortal.
momin is the canonical architect of vader's fortress, several sith temples, and created a key to the Door to the Dark Side and the World Between Worlds. jedi blew up his magnum opus ( and momin with it ), but momin survived by sealing his soul within his helmet and going dormant for centuries until his helmet was found by a young palpatine, who he tried and failed to possess.
palpatine locked momin's helm away in his vault for decades before gifting it and mustafar to his new apprentice, darth vader. momin builds vader's fortress and a key to the locked Door to the Dark Side to help vader bring padme back to life, then betrays vader and resurrects himself.
after a brutal fight in which momin wounds vader and gets him on his knees, vader uses momin's chatty nature against him, defeats him, and momin's spirit returns to the helmet, awaiting the next sorry soul to put it on and be devoured.
momin is wounded in his fight with vader but escapes alive, taking a portable key to the Dark Side and the World Between Worlds with him. he now roams this new galaxy, thousands of years outside his own time, looking to spread the worship of his Dark Mistress through his art, and destroy palpatine's "twisted distortion" of the sith.
he disdains the state of the modern sith and seeks to destroy the modern sith and palpatine, believing them an affront to "the true nature of the Dark Side." also, he's fucking petty and mad as hell that palpatine left him in that damn vault.
he's an evil criterion collection snob and completely fucked in the head. he's a HIGHLY DANGEROUS little freak, but he's also a chatty cathy desperate to show someone his stupid little projects. he WILL make you look at his shitty sculptures and he WILL be offended if you don't like it. you have been warned.