The Marines serve as the backbone of the World Government's military force, and across the world of One Piece, they are tasked with maintaining order and protecting citizens from the powerful pirates that control the Grand Line. At the top of the Marine hierarchy are three Admirals, the longest-serving of which (following Akainu's promotion to Fleet Admiral) is Admiral Kizaru.
Source：https://www.cbr.com/10-one-piece-devil-fruits-that-can-beat-admiral-kizaru/
