One Piece: Gear 5 - Luffy's Peak

Monkey D. Luffy is the protagonist of Eiichiro Oda's One Piece and he set out to sea with the aim of becoming the Pirate King in a time known as the Great Pirate Era. With the power of a Devil Fruit known as the Gomu Gomu no Mi, Luffy became a rubber man and has, on his journey, grown tremendously powerful. With time, Luffy has taken his abilities to the next level by inventing what he calls "gears."
During the Enies Lobby arc, Luffy invented his Gear Second and Gear Third. Following the two-year timeskip, Luffy came up with the idea of Gear Fourth with multiple forms. While all these power-ups were incredible and enabled him to take on some of the most powerful people on the seas, he didn't truly hit his peak until the Wano Country arc. In the fight against Kaido, Luffy finally tapped into what is his strongest transformation of all time and supposedly him at his peak – Gear 5.