This article contains spoilers for Star Wars: Crimson Reign #4.
A new Darth Plagueis, his Sith Master, who had experimented with the technique known as essence transfer. Palpatine killed Plagueis before he could truly master the technique, though, and he would need to continue researching it himself.
Darth Sidious sought the mask of an ancient Sith heretic named Darth Momin. When Momin died, he successfully possessed his mask, transforming it into one of the most dangerous artifacts the Emperor ever acquired. Anyone who wore the mask of Darth Momin would be possessed by his spirit, and the Emperor learned from him before ing it on to Darth Vader; Momin was an architect, and his was the mind behind Darth Vader's temple on Mustafar. He then attempted to use the Force vergence on Mustafar to restore his body, but was defeated by Vader.
Star Wars: Crimson Reign #4, by Charles Soule and Steven Cummings, finally reveals the final fate of Darth Momin. The comic is set decades after Vader fought Momin, and stars the Knights of Ren, who were assigned to break into Darth Vader's fortress. They chose to break in through the concealed entrance to the Sith shrine beneath the tower, and in so doing they stumbled upon the mask of Darth Momin. It seems Darth Vader simply discarded the mask after his victory, and never even bothered to pick it up. The mask made a desperate attempt to possess one of the Knights of Ren, but they destroyed it. And so Darth Momin, the Sith Lord who believed he had conquered death itself, was destroyed in the most embarrassing way possible.
The contempt Darth Vader felt for the twisted Momin is palpable. That ancient mask was deemed unworthy of his attention, the mask discarded, too worthless even to pick up off the ground. For nearly 20 years, the mask of Darth Momin had been trapped in the shrine he sought to use, unable to access it, the ultimate insult. No doubt Darth Vader felt a certain satisfaction at this - on the handful of occasions he bothered to him at all.
The Sith have always feared death, and their attempts to conquer it have always been cursed. This was why the Sith sought out the planet Exegol, a vergence in the Force where the veil between life and death was unusually thin, but Palpatine's use of the vergence led him to become trapped there after his resurrection. He thought he had achieved what Darth Momin had not, overcoming death itself, but in the end, he too was destroyed in Star Wars: The Rise of Skywalker. Unfortunately for the sith like Darth Vader, it seems there truly is no eternal escape from death in Star Wars.
Look for Star Wars: Crimson Reign #4 now available from Marvel Comics!
