Marshall D. Teach

Blackbeard is the captain of the Blackbeard Pirates, a member of the Inner Circle, and possibly the main antagonist of One Piece.

Role in Ultima
Blackbeard is one the most powerful members in the Organization. Because of his abilities he's consider a living doomsday machine.

He has yet to appear in Ultima, but when he does, you can expect the heroes to be in for a very, very, very difficult fight.