X (CLAMP)

From Viz:
Kamui Shiro is a young man who was born with the power to decide the fate of the Earth itself–a destiny he can barely bring himself to believe. But as other players in the prophecy begin to gather around him–the “Seven Seals,” with the power to protect the Earth, and the “Seven Harbingers,” who are fated to destroy it–he has no choice but to come to terms with his fate.