Кісараґі Саемон

A master of disguise, Saemon can morph into the form of others. Not only can he forge the voice of his enemy, but also clone their appearance. This bizarre chameleon-like technique makes for a silent, deadly assassin. Still, Saemon has a side very few see. As Okoi's oldest brother, there's no doubt that this cheerful soul loves his sister with all his heart. Because they are so close, they share something sort of a telepathic bond, as Saemon always senses when trouble's near. While Saemon is in the form of Yasamaru, he hold's Okoi's hand as she takes her final breaths. He is willing to do whatever it takes to defeat the Iga, and avenge his sister's death.

(Source: FUNimation's Official Basilisk Website)