Azul "Octopunk, Roi de Fort " Ashengrotto
About
His unique magic is called "It's A Deal". As long as someone signs a contract with him, he’ll be able to confiscate one of the target’s abilities. This can be a magical ability or a physical capability, such as a beautiful singing voice or ability to swim fast. If the target doesn’t fulfill the contract's conditions, they're bound to work under Azul indefinitely.
(Source: Twisted Wonderland Wiki)