Underhell is the AU home of UnderHell!Sans

Underhell is much like UnderTale, only with a more Hellish aesthetic, there is no Papyrus or Asgore in the current timeline, only Sans and Undyne.

The meeting

Error Sans tried to delete this AU some time ago, though UnderHell!Sans was able to drive him off, this event inspired UnderHell!Sans to leave his AU in search of a better world.