Revan was the name of an ancient Sith Lord. His name was revered by Sith cultists, his name seemingly bearing a huge significance in Sith history. The Sith Eternal army's 3rd Legion was named after the ancient Sith Lord.
Darth Revan's appearance in Star Wars: Knights of the Old Republic
Originally introduced in the Star Wars Legends continuity in BioWare and LucasArts's 2003 video game, Star Wars: Knights of the Old Republic, Revan was a Jedi Knight who served in the Mandalorian Wars. Revan broke away from the Jedi Order, becoming a Dark Lord of the Sith, and forming a Sith Empire that waged war against the Jedi and the Galactic Republic. Later suffering from amnesia, Revan was retrained as a Jedi to fight against his own Sith Empire. With Revan being the main playable character, players were able to customize Revan's physical appearance, gender, and even the story's outcome. Later on, The New Essential Chronology reference book established Revan's gender as male and canonized the light-side ending in the Legends continuity.
Revan's intended appearance in Star Wars: The Clone Wars
In 2011, Revan was initially intended to make his debut in Canon in "Ghosts of Mortis," the seventeenth episode in the third season of the Star Wars: The Clone Wars television series. Revan was supposed to appear alongside Darth Bane, serving as advisors to the Son, but they were ultimately cut from the episode in late production.
Dave Filoni, the director of the Clone Wars, was anxious about using the scene, but thought that the potential appearance of Revan and Bane would be a sight to behold. Later on, at the request of George Lucas, it was removed. Lucas thought that Sith Lords existing beyond death or outside of the Force was contradicting the established light side aspects and meaning of it. The idea later on was acknowledged and went far into development. The scene was able to make it to the animatics stage and can be seen in the bonus content on the Blu-Ray edition of Star Wars: The Clone Wars The Complete Season Three.
The cutscene is set in the Well of the Dark Side on the world of Mortis, where the Son, seemingly in anguish, confronts hidden dark-side spirits regarding the death of the Daughter, his sister. The hidden voices tell the Son to embrace the pain, prompting the Son to question their identities. Giant apparitions of Darth Bane and Darth Revan appear before the Son, proclaiming their intent to ensure the supremacy of the dark side. They inform the Son that having control over Anakin Skywalker, the Chosen One, was the key to his success. They also warn the Son of the existence of another who will control the galaxy.
Revan made his debut into canon through a brief mention in the 2019 reference book, Star Wars: The Rise of Skywalker: Visual Dictionary, written by Pablo Hidalgo. The reference book was written to aid the film Star Wars: Episode IX The Rise of Skywalker, diving deeper onto various aspects of the movie, including that of the Sith Eternal that emerged in 35 ABY.
In one section, it is referred that the Sith Eternal's army is consisted of various legions, each of which are named after various ancient Sith Lords. The Sith Eternal's 3rd Legion, happened to also be known as the "Revan Legion", later joining the rest of the military in the war between the First Order and the Resistance.
The 2022 novel, Star Wars: Shadow of the Sith by Adam Christopher, dove into the story of Luke Skywalker and Lando Calrissian's story many years after the events of Star Wars: Episode VI Return of the Jedi, exploring the growing threat of the Sith Eternal. At one point in the story, the Sith cultists were heard chanting the names of various Sith Lords, one of which was Revan. Other names included Plagueis, Noctyss, Sanguis, Kakon, Voord, and Shaa.
- Star Wars: The Clone Wars The Complete Season Three
- Star Wars: The Rise of Skywalker: The Visual Dictionary