Summary
- Darth Momin, a Sith heretic, was a feared and dangerous dark-side user who lived centuries before the prequel trilogy, though his influence extended into the days of the Empire.
- Momin was a gifted architect of dark-side superweapons. His creations included the Fermata Cage and a massive city-destroying superweapon fueled by his unique abilities in the dark side.
- Darth Momin's spirit lived on in his helmet, which was later used to design Fortress Vader on Mustafar seen in Rogue One and Obi-Wan Kenobi. He attempted to betray Vader but was ultimately defeated below the castle he created.
Although he's not the most well-known Star Wars villain, Darth Momin is one of the most dangerous dark-side users, having been a Sith heretic in life with an even darker legacy in death. Despite having lived hundreds of years before the prequel trilogy of Star Wars films, Momin's influence would stretch far beyond into the days of the Empire itself. Primarily recognized for his works as a sinister architect, Darth Momin's legacy has been featured in the Star Wars movies and shows more than once.
Originally referenced and created by Charles Soule in 2015's canonical Lando series for Marvel Comics, Darth Momin would make his full debut in Soule's 2017 run on Marvel's Darth Vader, showcasing Vader's very first days as a Sith Lord in the wake of Revenge of the Sith. During this period, Darth Momin's spirit left a dark legacy which can be seen on-screen both in Rogue One and in Obi-Wan Kenobi. Here's everything you need to know about Darth Momin and his unique Star Wars history as a Sith heretic.
Your browser does not support the video tag. Darth Momin Was The Most Horrific Sith Heretic Feared By His Fellow Sith 
Having lived between the years of 1,100-1,000 BBY, Momin became a Sith before Darth Bane's Rule of Two, meaning that the Sith were quite numerous during their ongoing conflicts with the Jedi Order. As a child, Momin was imprisoned for his experimentation with the dark side of the Force, creating horrible pieces of "art" using organic material such as the remains of his mother's pet. However, Momin's work caught the notice of the Sith Lady Shaa who freed and began training him as her apprentice. Wielding twin rapier-style lightsabers, Momin became a master duelist thanks to Shaa's teachings. He also used said lightsabers to sculpt his signature helmet.
However, Momin's heretical ideas quickly emerged. He hated the idea of the Sith calling themselves "Master" over the dark side or anyone else. To Momin, the dark side was to be served rather than dominated. Believing he was a supreme being and second to none, Momin killed Shaa yet refused to take an apprentice, believing that he had no time to teach as there was too much yet to be learned from the dark side.
Delving into the secrets of the dark side on his own, Darth Momin discovered all sorts of unorthodox ways of wielding the force, even by the standards of the Sith. This included the development of a new and unique version of Force lightning. This aided in the dark creations Momin continued to forge, and he quickly gathered a collection of acolytes who feared yet admired his great power.
Darth Momin's Superweapons Were Beyond Anything Else Created By The Sith Momin Created The Fermata Cage (And More) 
As a result, Momin gradually became a gifted architect of incredible dark-side superweapons. This included the Fermata Cage which was revealed after Crimson Dawn's Lady Qi'ra found and used the ancient device between the events of Empire Strikes Back and Return of the Jedi (as seen in Charles Soule and Steven Cummings' Hidden Empire). Capable of freezing beings or objects within a single moment in time, the Fermata Cage was the perfect prison that could also be unlocked, releasing its prisoners as if no time had passed.
In Hidden Empire, Qi'ra succeeded in trapping both Emperor Palpatine and Darth Vader in Momin's Fermata Cage, having used plans designed by her late Crimson Dawn predecessor Maul who sought revenge against his old master. However, the Knights of Ren betrayed Qi'ra and freed the Sith Lords, setting up their future service to both Kylo Ren and Palpatine as seen in the sequel trilogy. Nevertheless, it's made very clear that Momin's superweapon would have worked, irrevocably changing the trajectory of the entire galaxy had the Knights not intervened.
