Born a night elf and sorcerer, his pursuit of power led him to commit several horrific acts against his own people,[1] which earned him the nickname "the Betrayer" and to become the first Demon Hunter.

During the Third War, Tyrande released Illidan from millennia of imprisonment, hoping that the Betrayer would redeem himself by battling a returned Burning Legion.

He also appears in the Well of Eternity dungeon released later in Cataclysm, where the players travel back in time 10,000 years to the end of the War of the Ancients.

He appears briefly in cinematic cutscenes during the Demon Hunter introduction storyline (the first half of which begins shortly before Illidan's death in The Burning Crusade), sending his acolytes to a world called Mardum to retrieve a demonic artifact, the Sargerite Keystone, that would allow his forces to attack any world held by the Burning Legion.

A questline playable by all classes involves the naaru, crystalline beings that embody the Holy Light, seeking to resurrect Illidan as the chosen champion against the Legion.

Illidan is also involved in the final battle against Kil'jaeden aboard his Legion command ship in orbit of Argus, the former homeworld of the Draenei race.

[5] Illidan is a mobile, sustained damage assassin with very fast basic attacks and several "gap closers", who pairs well with heroes that can enable him.

[7] Illidan also became the first hero character of Hearthstone's tenth class, the Demon Hunter, introduced in the April 2020 expansion, Ashes of Outland.

By the time you and 24 eager guildies had trekked to the heart of Shadowmoon Valley and stood (attuned) at the gates of the Black Temple, ready to face him, it was all the average warrior could do not to soil his chainmail pants.

"[9] He was also listed #5 on Matthew Rossi of Engadget's "Top 10 magnificent bastards of Warcraft", since "his actions during and after the war were instrumental in the defeat of the Legion and the preservation of magic.

Even after enduring a 10,000-year imprisonment for his actions, Illidan managed to take out a key presence in the Legion by himself and claimed the power of the Skull of Gul'dan in the process.

"[10] Rossi further wrote that "He is one of the greatest manipulators of arcane power ever to live, the first to ever seek to stalk and kill demons, a prodigy and a madman.

"[12] While criticising the constant killing off of villains in Warcraft, Rossi also thought that Illidan's death was unfortunate, as "touted and hyped as the major threat of The Burning Crusade, Illidan's death atop the Black Temple is a waste of a major lore figure not because the fight isn't worthy of him or the culmination of an entire tier of raiding, but because with the release of Sunwell Plateau we find that Illidan wasn't actually the major threat—in fact, he was a stewing, impotently insane figure obsessing over his defeat at the end of Warcraft III and it was Kil'Jaeden who posed the true threat all along.

[14] Yannick Lejacq of Kotaku listed the references to the relationship between Tyrande and Illidan as one of the positive aspects of Heroes of the Storm, saying "Tyrande Whisperwind and Illidan Stormrage have a tenuous romantic past from their days together in World of Warcraft [...] It's a little nod to the World of Warcraft fans playing Heroes.