Ou Tenkun

Unanimous leader of the Kingou Juttenkun. A dark sennin with cleverness that matches Taikoubou. Has a habit of biting his fingernails when he thinks. He seems not to care about the bad consequences of his actions. Originally a human disciple of Genshitenson's named Ou Eki, he was traded to Tsuuten Kyoushu for Youzen in order to maintain relations between Kingo and Konron. Because Kingou does not allow humans, he was locked away until Dakki appeared and split his soul into three and giving them yokai bodies.

He has the paopei Kousuijin which causes acid rain, and the paopei dani, an animal type peopei like Youzen's Koutenken, but in the form of tiny ticks that secretly latch onto sennin and drain their energy as if they were constantly using a peopei. Also he has the ability to create warp gates in shape of water-like rectangular mirrors through which he can see and freely move himself or others.

(Source: Wikipedia, edited)