One Piece: The Free Shinigami

(No harem + won't kill Luffy + won't join the crew. This is essentially a book where the author makes up for some of their own regrets. If you're looking for all sorts of explosive kills, no need to enter.) For some unknown reason, a young man imbued with the powers of a Shinigami and a Hollow begins to rampage across this sea. The Seven Warlords, the Four Emperors, and even the Celestial Dragons are nothing but straw. (New author, writing style and ideas are slowly improving, please don't flame if you don't like it.)