The author of One Piece, Eiichiro Oda, is a master of mystery, suspense, and massive twists that change the foundation of everything that fans thought they knew. Because of this kind of storytelling, there are many characters that he has introduced into the story who are later revealed to be far more important than they seemed at first glance. While fans don't know much about him, Monkey D. Dragon is almost definitely going to fit this too.