Xehanort's Guardian

Xehanort's guardian is a dark entity, similar to a Pureblood Heartless, which is used by Ansem, Seeker of Darkness throughout the Kingdom Hearts series. It is first created by Terra-Xehanort, Ansem's original persona, to battle Aqua in Radiant Garden. The guardian is also temporarily used by Riku when he takes on the form of "Ansem" during his battle with Roxas. The guardian serves not only to protect its user from attacks, but also to fight for him when needed.