Board Thread:Speculation, Theories, and Rumors/@comment-25912037-20141223043619/@comment-5478429-20150205154942

Disregarding any characters' Super transformation and Final Bosses since that's a wee bit of a cop-out, I would say either: Shadow, since he has to use the Inhibitor Rings to keep his power in tow. And he has Chaos Control, Chaos Blast, Chaos Spear, Chaos Swiss Roll, among other things. or Metal Sonic, since he can basically match Sonic, but also doesn't need to rest, like Sonic would need to. Also, he has the Black Shield, can fly, is waterproof and can copy other characters' abilities. Robotnik done good with Metal.