First Question, Then Understand, and Finally Save!

There is such a novel whose author is very mysterious. It is so mysterious that it has become the most popular urban ghost story. Some people say that he is the reincarnation of the Celestial Master; Some people say that he is a tree spirit with thousands of years of experience; What's more, it is said that he is the Fengdu Emperor who rules over all ghosts. He holds a Beidi Ghost Slaying Sword and arbitrarily decides the injustices between humans and ghosts in the yin and yang realms. Li Tiannan, on the other hand, just wants to save every evil ghost equally. Write your own book by the way. "The next evil ghost, please tell me your story."