Question: who is z in one piece?
Answer: Zephyr (ゼファー, Zefā), also known as "Black Arm" Z (黒腕のゼット, Kokuwan no Zetto), is both a fictional character and deuteragonist from the One Piece series. He was the leader of the Neo Marines and the main antagonist of One Piece Film: Z. He was once a Marine admiral and instructor before his resignation.