Reincarnation Paradise

Su Xiao is a cold-blooded young adult who’s seeking vengeance for the death of his family, yet things ended up badly for him.
As he was taking his last breaths, he heard a voice calling him from dimensions, it was a strange system reaching him, asking him if he wanted to be saved, to be Reincarnated.
He just needed to accept a contract, Su Xiao didn’t have any choice but to do so, but he didn’t know what he signed up for!!
Travelling through worlds, doing extremely dangerous missions, collecting special items, levelling up, and even killing Protagonists…
But Su Xiao wasn’t any ordinary Contractor, Su Xiao was a Hunter!
The MC crosses over to: One Piece, Tokyo Ghoul, Naruto, Fullmetal Alchemist, Attack on Titans… and Author’s Original Worlds…