Nemesis Rex
From City of Heroes: Rebirth - Wiki
Overview
Nemesis Rex is an Archvillain and the leader of the Nemesis faction from an alternate dimension.
Heroes can find him at the end of an unofficial storyline (series of related missions but does not have end of storyline reward) about a war between two Nemesis factions in Stop the battle between Nemesis Army factions and make sure no innocents get hurt from Maxwell Christopher. (Levels 40-44)
Description
Nemesis has had over 100 years to perfect his armor and his combat skills. He is a formidable, and wily, opponent.