a being from another planet?....

Sonic, Amy, Tails, Shadow, Rouge, Knuckles, and Cream were fighting Eggman. Rouge was setting traps, Tails was helping to find the robots' cores, and Cream was healing the wounded since she was too small to fight. While Amy, Knuckles, Shadow, and Sonic were fighting, Tails detected a presence rapidly approaching Earth, and it wasn't Eggman's doing. Quickly, someone in a robe took down Eggman and the robots... Who could this new hedgehog be?