With One Piece's Wano Country Arc now firmly in the rearview mirror, the long-running shonen series is primed to enter a new, uncharted territory: its final saga. Monkey D. Luffy's journey to become the King of the Pirates once seemed impossibly far from coming to fruition, but his victory over Kaido — and, more importantly, the debut of his Gear 5 transformation — finally earned him the title Emperor of the Sea. However, as impressive as Luffy's recent exploits have been, they are only possible because of the influence of his legendary grandfather, Monkey D. Garp.
Source:https://www.cbr.com/one-piece-monkey-d-garp-mentor/