Mystery: the Soft Rice Witch

Wang Xin, who had lost his mind after performing a mysterious ritual, entered the world of novels he had read in his previous life. He had a beautiful cohabitant for nothing, but found out that his predecessor possessed the characteristics of an assassin. I have a bit of a crush on my mysterious cohabitant, but I eat an assassin myself. What should I do? Lord of Mysteries fanfic, Path of the Witch, the protagonist is chaotic and neutral.