Born 4000 years before the Battle of Yavin, Exar Kun was considered to be the greatest student of the Jedi Master Vodo-Siosk Baas. Kun eventually rebelled against his teacher in a bid for forbidden knowledge that he craved due to his fascination with ancient Sith lore.
This power he found was initiated by the spear of the ancient Sith Freedon Nadd on the planet Onderon. Eventually, Kun came across the tomb of the Sith Lord himself on the moon Dxun. Nadd would direct the young Jedi to the ancient Sith home world of Korriban to get a chance to regain physical form. Kun gave into the dark side and eventually enslaved the Massassi living on the fourth moon of Yavin and forced them to build temples across the moon.
Kun went and banished Nadd’s spirit as he never trusted the Sith Lord anyway. Afterwards he conquered the Krath cults star system.
Kun eventualy encountered Ulic Qel-Droma, a Jedi Knight who had lost his master to the Krath. Qel-Droma had been seduced by the dark side and the two had a duel until the spirit of Marka Ragnos appeared to them. Kun would be the Dark Lord of the Sith and Qel-Droma was to be his apprentice. Kun would instigate the Great Sith War which would devastate the galaxy for two years and he was successful is corrupting many new Jedi to the dark side.
His former master would also fall to Kun. However, as the way with many Sith Lords. He was betrayed. He was tracked to Yavin 4 and he tried to perform a ritual to transform himself into a Sith spirit but he was instead imprisoned on the planet by the Jedi who had created a barrier of light side energy which left him trapped for four millennia.
12 years after the Battle of Yavin when Luke Skywalkers Jedi Praxeum was established on the planet, Kun awoke due to the many Jedi students inhabiting the temple. He lured Kyp Durron to the dark side, and left Skywalker in a coma like state. However, the apprentices banded together and with the help of spirit Vodo-Siosk Baas, the spirit of Kun was finally destroyed for the rest of existence.
In 40 ABY, Tionne Solusar, a Jedi Master who had been among the Jedi that battled Exar Kun on Yavin 4, compiled a text about the history of the Force that discussed Kun's life and afterlife extensively. Itincluded a first-hand account from Streen,, another Jedi student of Luke’s, on his experiences battling Kun, among other stories from the Tedryn Holocron on the Sith Lord's life. Tionne couldn’t find any clue as to why Kun was unable to cause more havoc in the Jedi Praxeum. Corran Horn suggested that, after 4,000 years in solitude, the work it took to possess Kyp Durron and defeat Luke Skywalker had simply tired Kun out.
Exar Kun was first introduced in the Jedi Academy Trilogy as a vision to the Jedi Gantoris. From there, the Tales of the Jedi comic books from Dark Horse would fully elaborate and tell his history. Once again showing how everything in the Expanded Universe was connected and it was all one large continuity. (A point that really doesn’t need to be made anymore but it is still worth mentioning.)
The character was created by Kevin J. Anderson. Interesting enough when Anderson was creating the character he wasn’t sure whether Kun should be a “Dark Jedi,” or a Sith Lord. However, he decided that Kun should be a Sith when a man named George Lucas voted that Kun should be Sith.
Kun was incorporated in Tales of the Jedi and was the first character in the Star Wars franchise that wielded a double-bladed lightsaber which led to George Lucas giving one to Darth Maul in the Phantom Menace due to his love of the idea.
Exar Kun was a very important character to the Expanded Universe he inspired much of the lore of the franchise as well as an influential character for the films that came out after he was created.
Tales of the Jedi: The Golden Age of the Sith 0: Conquest and Unification (Mentioned only)
Tales of the Jedi: Dark Lords of the Sith
Tales of the Jedi: Dark Lords of the Sith audio drama
Star Wars: Tales of the Jedi—The Sith War
"Shadows and Light"—Star Wars Tales 23 (Mentioned only)
Tales of the Jedi: Redemption 1: A Gathering of Jedi (Mentioned only)
Tales of the Jedi: Redemption 2: The Search for Peace (Mentioned only)
Tales of the Jedi: Redemption 5: Master (Mentioned only)
Knights of the Old Republic 6: Commencement, Part 6 (Mentioned only)
Knights of the Old Republic 9: Flashpoint Interlude: Homecoming (Mentioned only)
Knights of the Old Republic 32: Vindication, Part 1 (Mentioned only)
Knights of the Old Republic 33: Vindication, Part 2 (Mentioned only)
Knights of the Old Republic 47: Demon, Part 1 (Appears in flashback(s))
Knights of the Old Republic 48: Demon, Part 2 (Mentioned only)
Knights of the Old Republic 50: Demon, Part 4 (Mentioned only)
Lost Tribe of the Sith: Sentinel (Mentioned only)
Star Wars: Knights of the Old Republic (Mentioned only)
Star Wars: Knights of the Old Republic II: The Sith Lords (Mentioned only)
Timeline 9: The Mandalorian Wars (Appears in hologram)
Timeline 10: The Exar Kun War (Appears in hologram)
Timeline 11: Rebirth of the Sith Empire (Indirect mention only)
Star Wars: The Old Republic (Mentioned only)
Star Wars: The Old Republic: Shadow of Revan (Appears as a ghost or a spirit)
Star Wars: The Old Republic: Knights of the Fallen Empire (Mentioned only)
Knight Errant (Mentioned only)
Darth Bane: Path of Destruction (Mentioned only)
Bane of the Sith (Mentioned only)
Darth Bane: Rule of Two (Mentioned only)
Darth Plagueis (Mentioned only)
The Wrath of Darth Maul (Mentioned only)
Darth Maul: Shadow Hunter (Mentioned only)
Star Wars Episode I Journal: Darth Maul (Indirect mention only)
Star Wars: The Clone Wars (Mentioned only)
MedStar II: Jedi Healer (Mentioned only)
Star Wars: The Clone Wars: Lightsaber Duels (Mentioned only)
Shadows in the Force (Mentioned only)
Star Wars Galaxies: An Empire Divided (Appears as a ghost or a spirit)
"Le facteur X"—Casus Belli 115
Jedi Search (First appearance) (Vision to Gantoris as "Dark man")
Dark Apprentice (First identified as Exar Kun) (Appears as a ghost or a spirit)
Champions of the Force (Appears as a ghost or a spirit)
I, Jedi (Appears as a ghost or a spirit)
Children of the Jedi (Mentioned only)
Darksaber (Mentioned only)
Jedi Academy: Leviathan 1 (Mentioned only)
The New Rebellion (Mentioned only)
Specter of the Past (Vision to Luke Skywalker)
Vision of the Future (Mentioned only)
Junior Jedi Knights: The Golden Globe (Mentioned only)
Junior Jedi Knights: Lyric's World (Mentioned only)
Junior Jedi Knights: Promises (Mentioned only)
Young Jedi Knights: Heirs of the Force (Mentioned only)
Young Jedi Knights: Lightsabers (Mentioned only)
Young Jedi Knights: Return to Ord Mantell (Mentioned only)
The New Jedi Order: Dark Tide I: Onslaught (Indirect mention only)
The New Jedi Order: Agents of Chaos I: Hero's Trial (Indirect mention only)
The New Jedi Order: Dark Journey (Indirect mention only)
The New Jedi Order: Destiny's Way (Mentioned only)
The New Jedi Order: The Unifying Force (Indirect mention only)
Legacy of the Force: Invincible (Mentioned only)
Crosscurrent (Mentioned only)
Fate of the Jedi: Outcast (Mentioned only)
Fate of the Jedi: Backlash (Mentioned only)
An Apology (Non-canonical mention)
Matt Wilkins on the first appearance of Exar Kun