Monkey D. Luffy is at the center of a major brewing war in One Piece right now. The story is already in the Final Saga, and although it will be very elaborate, the final war is on the cusp of beginning. Luffy has become a Yonko recently, which is a massive accomplishment, but there are bigger enemies for him to face still. It is safe to say that Luffy's upcoming battles are going to be very exciting, and they will see him make use of his strongest powers, such as Gear 5.