Dark Legion's debut in The Chronicles of Sonic the Hedgehog: Rise of the Heroes. In the game, Dark Legion is said to be a fearsome demon who once reigned over the Earth causing nothing but destruction and chaos. He was then sealed for eternity inside the Earth's core. Centuries later, Dark Legion contacts with a being named Immarius. through visions. He grants him a wish and builds him an indestructable armor. In return, he asks for Immarius to gather his army and go to Earth to resurrect him.Dark Legion does not appear in the story of the game and is only mentioned several times by various characters until the Final Story, where Immarius reveals himself to be just a mere soldier following his master's bidding. After Immarius successfully resurrects Dark Legion, he creates a huge black hole which consumes the entire planet. The heroes battle Dark Legion with all they've got, Eggman in his Egg Abolisher and then the Super Hedgehog Trio battle him as well. However, it is Zeline and Sonic who truly defeat Dark Legion. Zeline uses Chaos Control to teleport Dark Legion and herself into another dimension in order to seal him for eternity. Dark Legion is never heard from again.
Dark Legion makes a small cameo during Immarius' backstory cutscene in the Final Story. He is also mentioned by Immarius once.
Sonic the Hedgehog 2.0Edit
Near the appearnce of Mega Sonic in The Fifth Final Battle, Sonic is in Mephiles's Locker, a.k.a. the Isle of Death, only the island is on fire. I mean, LITTERALLY on fire! And then, he sees a sinister, and fiery face in the smoke. He would later know it would be the face of Dark Legion. It is unknown whether he would appear in one of the books/moves.
Dark Legion is a fearsome sight. He resembles a demon god. He is coloured red. He is enormous in both shape and size. He has 6 arms attached to his body; two of which wield huge swords. He has no legs; instead, he has multiple huge tenticles which are attached to some big debris floating around. He has hue horns in his head. All in all, he is based on Diablo.