Li Sei is the father of Nataku and commander of Chintou pass, a connection point between Chouka and northern Yin provinces.

He trained in the senning world before, but failed many times, and that is why he had no paopei. Later, he returned to train again and received paopei Reiroutou that looks like an obelisk, shoots ghosts, and uses the power of the user's grudge to curse someone to death.