The end of One Piece‘s epic tale is approaching, and the identity of Luffy’s final opponent is currently unknown, but there are at least five individuals who’d each bring an emotional and narratively brilliant conclusion to the future Pirate King’s story. Some villains, such as the secret ruler of the World Government, Imu, presented themselves well into the series, but other contenders for the role of Luffy’s final boss in One Piece have been a part of the story since the beginning.

https://screenrant.com/luffy-final-boss-most-likely-one-piece-ranked/