One Piece: Collapse of the World

Devil Fruits are excellent experimental materials, so naturally we should seize as many as possible. Things like Six Styles and Haki are not too complicated, and you can come up with new moves by just experimenting. Luffy, your brother will help you become the Pirate King. Ace, if you want to help me become the Pirate King, Sabo, come be my advisor! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.