During his reign as the Emperor’s murderous force of order and terror in the Star Wars galaxy, Darth Vader rarely came across an enemy he couldn’t beat, until he had a run in with the Knights of Ren who were successful in defeating Vader and, in doing so, exposed his greatest weakness.
The Knights of Ren are an ancient order of masked Force users who follow the ways of the Ren–a religious philosophy that requires one to wield a red lightsaber and practice in the Dark Side of the Force. While the Knights of Ren use the Dark Side, they are not Sith as they do not adhere to the Sith’s power-hungry totalitarian ways and in no way recognize the Sith Rule of Two in the structure of their religion. The Knights of Ren are basically anarchistic zealots who roam the galaxy using the Force however they see fit–spreading glorious chaos in the name of their sacred Ren.
Related: Star Wars Reveals the R-Rated Reason the Knights of Ren Don't Speak
In Star Wars: Crimson Reign #4 by Charles Soule and Steven Cummings, the leader of the criminal organization Crimson Dawn, Qi’ra, approaches the Knights of Ren and asks them to join her on her quest to destroy the Empire. Since they don’t fall in-line with the ways of the Sith, the Knights of Ren fear they will eventually be hunted down by Darth Vader and killed just as the Jedi were before them. Before they become a target on Vader’s radar, they decide to join Qi’ra and take the fight to the Empire now, when Emperor Palpatine least expects it. The mission Qi’ra gives them, however, is a dangerous one: break into Darth Vader’s castle on Mustafar and steal a mysterious key from his vault. While the mission was filled with dangers, including an unexpected appearance from Darth Vader himself, the
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