Origin of the AUOkay, So LossTale is pretty much a post-genocide route, but also,okay here's the story:
The monsters had all been killed except for sans, Alphys, Grillby, y'know, the ones you don't kill. Once the human escapes the underground, they tell others that they slayed all of the monsters, but they started sending groups of people down there to kill the ones that are left, so they had to run and actually dig DEEPER underground. Grillby's is shut down and muffet's is outta business. Most of the characters are cannibals, so everyone tries to hide from eachother. Alphys killed herself btw. The remaining characters gave up pieces of their souls so everyone could live again, so everyone in the AU has 1 hp.