Although he tried many methods, his spiritual power was constantly drained here. Then why hasn't he collapsed yet. He says that he doesn't want to lose his power, and that's why he's allowed himself to be taken by the spirit grass. If you can find the grass, you can revive Miss yan. However, it's in a dangerous location, and ordinary people won't survive there. As long as he can revive her, he says, he'll even be willing to kill a bunch of people to do it. Oh, and he says that even if you kill him, he can't take the grass away from his dead body. He swears that no one can steal the grass from him, even if he gives up his life for the sake of the grass. He wants to kill you, but he can think of nothing else to do. He's just going to kill her anyway, because she reminds him of all the people he'd killed in the past, and she reminds the demon king of all of them. He tells himself that he needs to think about it, because the grass has matured, and now he wants to take it away from her.