One Piece: I Am the King of Joy

A sharp-tongued young man named Lin Yang is reborn in Foosha Village with a six-year-old body and a "Jokes System." He binds Garp as his grandpa and becomes the foul-mouthed fourth little brother of Ace, Luffy, and Sabo. From the start, he gets a cheat: top-tier Haki, sealed until unlocked, and a talent for boosting his teammates' physical abilities! He gives them an early preview of New World skills and uses internet memes to roast the three future Emperors. Refusing to eat a Devil Fruit, he vows to become a legend through physical combat. He joins Luffy's crew as his right-hand man, speeds up the story, beats the Shichibukai, kicks the Admirals around, and changes the outcome of the Paramount War.