In the Domain of Apocalypse on Battleworld, Nemesis worked for Mister Sinister alongside Dark Beast. Over time he had experimented on himself and absorbed the powers of over 300 mutants into himself, being increasingly more powerful each time. On instructions from the human council, Nemesis created a virus that was capable of wiping out the entire mutant race. When the virus was released, Nemesis tried to play both sides and attempted to convince the X-Men to stand alongside him to fight Emperor Doom. The X-Men knew Nemesis had betrayed them though and they fought back, but were unprepared for how powerful he was. He killed a number of mutants before he was destroyed by the Phoenix-empowered Jean Grey.