Undertale: An Unexpected Visitor

In the vast and varied world of AUs, there are always unique existences. As the stories familiar to everyone gradually fade, perhaps other worlds still exist. This is one of them.

Disclaimer: This novel is fan fiction related to Undertale. There's no need to worry about who the protagonist is.

I may try to post character designs and settings on Bilibili later.

This is my first time writing a novel, and my abilities are limited. If there's anything I can improve, please be sure to point it out.