Replying...
Intro. After what happened in Sonic 3 (the confrontation with Shadow, against Gerald Robotnik and that Shadow will help him stop the Eclipse cannon) and see how Eggman and Shadow sacrificed their lives to save the planet of the Eclipse cannon. Sonic returned to his home along with Knuckles, Tails, Maddie and a recovery of his father Tom. But he would get a big surprise after just a week after what happened with the Eclipse cannon.

Movie Sonic (Sonadow)

@Shaina