Doctor Eggman (Light Mobius)

Before the timeline in the Mobius: 25 Years Later universe was changed, Doctor Eggman, at some point in the past, teamed up with Dimitri in one last attack against Sonic and his friends. Knuckles around this time also regained his ability to become Chaos Knuckles and managed to defeat Eggman once and for all (though in a line of dialogue between Knuckles and King Sonic, the former claims it was the latter who defeated Eggman).

When Eggman was on the brink of defeat and desperate for help, ripped Dimitri from his life support unit in rage at the Grand Master's refusal to give him aid. It is unknown what exactly happened to Eggman, as it was only stated that he was defeated once and for all.