Tenkou

Tenkou is a wicked, powerful man and the King of the Shitennou (Four Heaven Kings), whom he controls and commands. He is even more powerful than Nakago, who served him, and even more evil. Tenkou believes he is a god, and it is his dream to attain the ultimate power of the "Shi Jin Ten Chi Sho", and become the ruler of both the book world and the real world. Tenkou is extremely powerful, merciless, and cruel. He kills people with no hesitation or remorse, and controls others, forcing them to acknowledge his superior powers.
From Fushigi Yuugi - The Fire of Suzaku's Wings