Luffy is essentially only using Gear 4 in one arm. Step aside! It's time for a little Gear 4. Luffy Fans saw this in One ...

Some Devil Fruit powers in One Piece ... these four pairs. - Oda in reference to the Ton-Ton Fruit versus the Kilo-Kilo Fruit, the Ice-Ice Fruit versus the Snow-Snow Fruit, the Arms-Arms Fruit ...