Master Xehanort

Xehanort is a major character in the Kingdom Hearts series, and is the central antagonist of the Dark Seeker Saga.

A Keyblade Master who once taught Ventus, Master Xehanort believes that darkness and light should exist in perfect balance, and for this reason, he seeks to conquer Kingdom Hearts and recreate the worlds according to his wishes. Through his many different incarnations, including Terra-Xehanort, his Heartless, Ansem, Seeker of Darkness, and his Nobody, Xemnas, Xehanort is ultimately responsible for the series of events that repeatedly threaten the worlds with destruction, including the mass release of Heartless into the Realm of Light, and the creation of the Nobodies and Organization XIII. He has also brought tragedy to many that have crossed his path, including Sora, Riku, Kairi, Terra, Ventus, and Aqua.

Young Xehanort acquired the ability to travel through time from his future self's Heartless, and he used it to manipulate events so that his future self's plans would come to fruition.