E-123 Omega is the last and most powerful of Doctor Ivo "Eggman" Robotnik's E-Series robots.Omega's only allies are Shadow The Hedgehog and Rouge The Bat.In Sonic Heroes (which was Omega's first game),he was sealed in a secret room,and awakened by Rouge after releasing Shadow from a chamber.Since then,he's been taking his revenge out on Eggman.