About Marshall D. Teach
Marshall D. Teach, most commonly referred to by his epithet "Blackbeard", is the admiral of the Blackbeard Pirates, and one of the Four Emperors that rule over the New World. He is the son of the legendary pirate Rocks D. Xebec and his wife Eris, making him a member of the nearly-extinct Davy Family and a descendant of Davy D. Jones, which is only known to a small number of individuals, including his own crew, the Five Elders, and Nerona Imu. He is the only known person in history to wield the powers of two Devil Fruits.
Teach started out his pirate career as an apprentice of the Whitebeard Pirates, then later became a member of the crew's 2nd Division. However, he murdered Thatch, the 4th Division Commander, in order to steal the Yami Yami no Mi, a rare darkness-based Logia Devil Fruit with the power to nullify the Devil Fruit abilities of others. He then fled from Whitebeard's crew and, after defeating the infamous 2nd Division Commander Portgas D. Ace and handing him over to the Marines, was awarded a position among the Seven Warlords of the Sea. He only held the position briefly, though, using it to infiltrate the great underwater prison Impel Down and escaping with multiple infamous Level 6 prisoners recruited into his crew.
Upon arriving at the Summit War of Marineford, he resigned from his position and murdered Whitebeard, mysteriously stealing his quake-generating power. This, along with his victory in the Payback War and conquest of the majority of Whitebeard's territories during the timeskip, resulted in his acknowledgement as one of the Four Emperors, as well as him being considered a part of the "Worst Generation" along with the eleven Supernovas. After the Rocky Port Incident, he turned the island of Hachinosu into his base of operations with the ambition of having it officially accepted into the World Government as the Blackbeard Kingdom.
Teach initially had no bounty; however, after resigning from the Seven Warlords, recruiting several dangerous criminals to his crew from Impel Down, and becoming one of the Four Emperors, he received a bounty of 2,247,600,000. Following the downfalls of Kaidou and Big Mom during the Wano Country Arc, his bounty was increased to 3,996,000,000 for unknown reasons.