Z, also known as "Black Arm" Zephyr, is a former Marine admiral and the main antagonist of the One Piece Film: Z. Once a revered leader and mentor within the Marines, Z grows disillusioned with the organization after a series of personal tragedies. He forms the Neo Marines, aiming to eradicate all pirates by destroying the New World. Despite his villainous role, Z is a complex character driven by a deep sense of justice and a desire to protect the world from the chaos he believes pirates bring.