Xu Xiannian was pulled into a strange story with rules. After clearing the strange story, the weirdness in the strange story inexplicably sent her an invitation to become an NPC. Working hard to clear levels and so on, there is no comfort like lying down as an NPC.
It's actually more like an infinite flow than a ghost story. It's a boring product of morning and evening self-study and casual classes. It can be used as a pastime. If you feel there are problems with the plot, you can quit. The author doesn't have such a high IQ. It really requires too much brainpower to write.
