Ansem "Xehanort's Heartless" Seeker of Darkness
About
Ansem reappears as one of the main antagonists for Kingdom Hearts 3D: Dream Drop Distance, having being brought from a moment in time by Young Xehanort. Ansem takes advantage of the Sleeping Worlds to mess with Riku by attempting to open the youth's heart to darkness again. After being defeated by Riku in the Sleeping World version of the World That Never Was, later appearing in the Organization's attire, Ansem attacks Riku and Mickey to hinder them from interfering in Xehanort's attempt to convert Sora. By that time, it is revealed that Xehanort's scheme included Ansem making use of the bodiless form to make contact with Young Xehanort to enact the back-up plan.
Ansem is voiced by Akio Ōtsuka in the Japanese version of the series. In the English version, the character was originally voiced by Billy Zane in Kingdom Hearts and now by Richard Epcar in all subsequent releases/remakes.
(Source: Wikipedia)