You could actually say : Adolph Hitler ! He started out as a hero to the German people in the early 30's and they worshiped him. Then he took his path of pure evil and turned out to be one of the worst villains in History.
Who are some real people that started out as a hero only to end up as a villain?
Honestly and please don't laugh but, My mom.
She used to be caring, loving and all that but then she became abusive, upset and constantly angry. We aren't allowed to see her anymore, it's for the best, ya' know?
Napoleon Bonaparte.