Donquixote Doflamingo

The string-wielding usurper king of Dressrosa, alias 'Joker'.

Donquixote Doflamingo is the captain of the Donquixote Pirates in One Piece, the usurper king of Dressrosa and a former member of the Seven Warlords of the Sea.

Quick Facts

Crew: Donquixote Pirates (captain)
Devil fruit: String-String Fruit
Also known as: Joker

Facts from the source article.

Background

His String-String Fruit lets him control people with puppeteer-like movements of his fingers and shoot sharp, thin strings that cut, form clones of him and hook onto clouds so that he can fly, and he can use all three types of Haki. He was born a Celestial Dragon, but his father, Donquixote Homing, gave up that life to live as an ordinary human; the family was hunted and tortured, and Doflamingo killed his father and carried his head to Mariejois in a failed bid to regain his title. Under the alias "Joker" he works as a broker and owns a large auction house on the Sabaody Archipelago where people are sold as slaves. Once the Straw Hats and the people of Dressrosa expose his crimes, Luffy defeats him, his title is revoked, and he and his crew are arrested.