One Piece's world is in a constant state of turmoil, where almost everybody is doing whatever they want. Freedom to pursue one's whim is an unspoken pirate motto. However, it's also a world where one's occupation doesn't guarantee their moral tendency. Pirates can be good, just as Marines can be evil, but that also doesn't mean all the Marines are corrupted or that every pirate is good. Former Admiral Aokiji, aka Kuzan, and the Blackbeard Pirates are the perfect example of this philosophy, especially after Kuzan joined Blackbeard.
Source：https://www.cbr.com/one-piece-chapter-1081-why-kuzan-joined-blackbeard-pirates/
