There Are Fierce Ghosts Everywhere, but I Can Suppress Them All with One Person

Zhang Yan suddenly entered the restricted "old dormitory" at the university and saw that there were ghosts in the world. After escaping from death, he understood that there were ghosts in the world and understood the laws about ghosts. "Humans and ghosts coexist." "People can only deal with ghosts from the past, not the ghosts of the present." "Because of symbiosis, humans and ghosts deal with each other." "Understand the killing patterns of ghosts."