Thread:Heroic412229/@comment-27032473-20160401001551/@comment-26780692-20160610153958

Welp, that really depends on the direction you wanna take it but I'll help.

Maybe, Zexus has arisen to his perfect form after retrieveing all Chaos Emeralds. Maybe during the story, he threatens to awaken a monster that'll destroy the world and maybe the awakening point is Angel Island. So, all Sonic characters may gather up there for an epic showdown. If Eggman is working with the heroes, maybe he turns on them at that point as well, raising the stakes a bit more.