Coop and Megas from the early-to-mid-2000s animated series Megas XLR takes on Jim Carrey's Dr. Robotnik in his Death Egg Robot (Great Eggman Robo?) from the Sonic the Hedgehog 2 film.
The fight takes place in an abandoned Green Hills (the citizens--including ALL of the Wachowskis [this does include Tails and Knuckles]--have all evacuated).
I will be spotting Dr. Eggman the Master Emerald here, because in my opinion, it would be the only thing that could be a potential answer to Megas' "magic button".
Round I) Normal Coop takes on Robotnik.
Round II) Future/Alternate Coop invades and takes on Robotnik. The Master Emerald is MANDATORY in this scenario. After all, Future Coop saw Megas as a "worthless & obsolete toy".