This is a AU where frisk has ran so many genocide runs that sans finally took action but told Undyne and Mettaton about the resets that the human can do because of the genocides. Already all of the monsters in the ruins including the ex-queen Toriel has died, and all of the monsters in snowdin including papyrus died leaving his red scarf behind. W.D. Gaster is sans and papyrus Dad but was shattered across time and space, Arial is sans and papyrus mom but was shot by a human (yellow soul). 