|Human Partner||Akiyama Ryo|
Millenniumon is the main villain in WonderSwan game storyline (Digimon Adventure: Anode Tamer & Cathode Tamer, Digimon Adventure 02: Tag Tamers & D1 Tamers and Digimon Tamers: Brave Tamer). In Brave Tamer it is revealed that he is a temporal paradox, revealing that he was Ryo's original partner, a fusion of Mugendramon and Chimairamon, becoming Millenniumon, and soon after, Zeed Millenniumon, who is the mastermind behind the events of Digimon Adventure, giving rise to Apocalymon (which in turn gave rise to the Dark Masters' Mugendramon) and Meicoomon (through Apocalymon). Zeed Millenniumon eventually Jogressed with Monodramon at the end of Brave Tamer.
Millenniumon was also responsible for the creation of Digimon Kaiser, a dark personality of Ichijouji Ken controlled by a Dark Seed that was originally intended to reach Ryo. Controlled by the Dark Seed, the Digimon Kaiser created Chimairamon.
|Ultimate||Mugendramon (with Chimairamon) |
Millenniumon serves as the final boss of the game, fought after defeating all the previous bosses (Devimon, Etemon, Vamdemon and Piemon) as well as one of the Digimon that formed him (Chimairamon in Anode Tamer, Mugendramon in Cathode Tamer) in a row. Upon being defeated by Akiyama Ryo, Yagami Taichi is freed and returns to his own world, finishing the game.
Millenniumon appears as the final boss in the game.