Kauron

Kauron is the young lord of Hades, where he lives with his younger sister Iria, whom he cares for deeply. He has the ability to make "life flowers," which can control a person's life or death by destroying the flower. He wishes to "purify" the world (I'm not going to say how, I said I wouldn't put too many spoilers in this section), and manipulates other demons in order to do so, especially Zadei, using Teteiyusu's life flower.