Harry Potter the Magical Worlds Hero

Xover between Harry Potter and Ratman Manga. A young abused Harry was made to clean the attic one day when Petunia wanted to make the boy suffer by throwing out his mothers belongings. His aunts plan seemed fool proof he discovered a strange watch. When he put it on his life changed from the cruel life he lived. Now living a new life Harry goes to Hogwarts as the Magic Hero Ratman.