Fan Casting Plot twist in Dawn of Sonic: the Scourge of Mobius

At the final battle, Scourge saw Eggman doing something with the portal device that brought him here. And what does Eggman do? He tells Scourge that he actually liked Scourge, but he cannot trust him. Then he opened the portal to bring out enemies from other universes: the Deadly Six from the IDW Comics, a variant of Nine from Sonic Prime (if he didn't turn good), and Boom Shadow (Shadow from Sonic Boom)!!!! He's also had the time to reunite with an old family member or two: Snively and Eggman Nega!!!!!!!