According to Oda himself, he intended for One Piece to be a fight Against the Four Emperors at first, but the involvement of the Shichibukai is what made the series as long as it is. The reason ...
Boa Hancock was introduced in One Piece as a Shichibukai, which means that she was a pirate allied with the World Government, giving them her strength, and in return, gaining a certain level of ...