A mysterious and powerful villain who is after Sakura's feathers. He is later revealed to be a direct descendant of Clow Reed and well aware of the powers of the Dimension Witch. He was the one who imprisoned the real Syaoran and created the Syaoran who is the protagonist of Tsubasa. Though he already possesses the power to cross dimensions like the High Priest of Clow and Princess Tomoyo, he seeks the power of Sakura's wings, which surpasses the power of all who can cross dimensions, and the power that lies under the ruins of the Clow Country in order to "bring back a dream that has already ended".
Manga Spoilers
From Wikipedia entry.