Frieza on 24 March 2010
As far as strongest main characters go Sora is definitely stronger than Kratos and most likely all video game characters except a few.
In his final battle with Xemnas he swats a skyscraper through a metal barrier like he was playing tennis, then with Riku he deflects every single laser that was thrown at him. Lasers move at light speed. Sora would give Goku a run for his money.
