E-123 Omega is a Miniboss canidate for SSB4 from the Sonic Universe. In his arms he has many concealed weapons such as laser cannons, flamethrowers, and machine guns, making him a force to be reckoned with.
Part of the E-Series of robots built by Eggman, he was the last and the most powerful. He was once one of Eggman's servants, but after being locked away for unknown reasons in an abandoned Eggman base with the presumed dead Shadow, he was angry at Eggman and plotted revenge against him, while Shadow wanted answers about his past due to gaining amnesia from his fall from the ARK colony to Earth after defeating the Final Hazard with Sonic, and Rouge wanted Eggman's secret treasure. He is good friends with Shadow and Rouge, perhaps his only friends.