Marshall D. Teach, better known as "Blackbeard" is one of the antagonists from the One Piece game series. He is the captain of the Blackbeard Pirates. As a member of the Whitebeard Pirates, he killed his crew mate Thatch to get hold of the Devil Fruit he has sought for several decades. For betraying Whitebeard's crew, and the murder of his crewmate, he is pursued by Ace who eventually confronts him.
After defeating Ace and turning him in to the World Government, he is appointed Crocodile's replacement as one of the Seven Warlords of the Sea, a position he promptly abuses to expand his crew with prisoners from Impel Down and resigns once he is finished. After slaying Whitebeard in battle, Blackbeard somehow manages to take Whitebeard's place as one of the Four Emperors.
He uses the ability of the Logia-type Devil Fruit: the "Dark-Dark Fruit" to create, control, and transform into darkness at will, and create and control black holes through by an ebbing, flowing, shroud of darkness, shown to possess a strong gravitational pull, as well as the ability to disable the Devil Fruit powers of others, as long as he is touching the person.
He was once a member of the Whitebeard Pirates' second division, but defected after murdering a fellow crew member, Thatch, the 4th division commander, to obtain his Devil Fruit, the "Dark-Dark Fruit" to start out his own pirate career.
Later, prior to the two-year timeskip, The Straw Hat Pirates first encounter Blackbeard at Mock Town when he hears that the Sky Islands exist and boasts how the pirate's dreams will never cease. He then tries to capture Luffy at Mock Town, but is driven out.
Blackbeard was made and briefly held the position of one of Warlord of the Sea after a brutal fight, for defeating and capturing Portgas D. Ace, and then handing him over to the Marines, before resigning upon returning from Impel Down with Level Six prisoners. After killing Whitebeard with the help of his new crew, Blackbeard somehow adds his former captain's Devil Fruit ability to his own and manages to take Whitebeard's place as one of the Four Emperors.