Darth Bane is one of the most significant Sith Lords in Star Wars, but Revan from Star Wars: Knights of the Old Republic proved to be even more important to the Sith. While Bane's Rule of Two is still an integral aspect of Star Wars canon, both he and Revan had detailed histories in the Legends continuity, allowing Revan to influence the Sith just as much as Bane did. Because Revan is confirmed to exist in canon, it's possible that his history from Legends still applies and makes him an essential part of Sith history.
Although Revan returned to the Jedi Order in KotOR's official ending, this made him even more important to the Sith. He became one of the most memorable Star Wars characters to have walked both paths, something that Bane never did. This may seem like an advantage Bane had over Revan regarding the Sith, but Revan was still more important, with his story greatly influencing Bane and his line of Sith Lords.
Bane Developed The Rule Of Two From Revan's Teachings
Bane firmly established the Sith Rule of Two that would be followed for a millennium, but he only developed this ideology from studying Revan's Holocron. Revan understood that there could only be one true Dark Lord of the Sith, who in turn should have one apprentice at a time. There could be other Sith servants and dark agents, but Revan ensured that he would have the highest power and that only one apprentice would be strong enough to challenge him. When Bane determined that the Sith should undermine the Republic from within, he adopted a more literal approach and declared that there would only be two Sith at any time.
Revan Foreshadowed The Sith's Eventual Defeat
Bane studied Revan's history during his time at the Sith Academy on Korriban, meaning he should have realized that Revan's story foreshadowed the Sith's eventual defeat. Revan was ed as one of history's greatest Sith Lords, but he later returned to the light side and helped the Jedi defeat his former apprentice, Darth Malak. He only did so because Malak tried to kill him when he was still a Sith Lord, proving that the instability of Sith trying to kill each other remains even with two true Sith Lords. Revan's return to the light also foreshadowed the end of Bane's line when Anakin Skywalker returned and destroyed Emperor Palpatine.
The Rule of Two arguably made it easier for the Sith to be destroyed, as there weren't any Sith to replace Palpatine or Darth Vader. The Sith did return in many forms throughout Legends, but it would take years for them to rise in number again after Return of the Jedi. Bane's Holocron would later scoff at Darth Krayt ending the Sith Rule of Two for supposedly diluting the power of the dark side with so many Sith. Revan's influence on the Sith perfectly represents the light and dark aspects of his character from Star Wars: Knights of the Old Republic, highlighting his importance to the Sith over Darth Bane.
