Seishiro Saiba

Seishiro Saiba, known as Seishiro the Cosmic Devil, is a former pirate and member of the Yonko during Arleigh D. Shiraz's time. Despite having a masculine name, Seishiro is a woman. As the last remaining member of the previous generation of the Yonko, she was replaced by Yuki Karjalainen three years before the current storyline.