Basically the idea of my HorrorTale take is that Frisk got fucked up by the amalgams, so did Alphys and basically Hotland and yonder are now owned by the amalgams, Asgore has died due to not being able to be supplied with food and water and such, thus making the underground even smaller. Big difference in my take is that instead going delusional everyone is trying to live in this new environment, Papyrus is the new scientist and Sans is his teacher.