undertale au · skeleton · nightmare sans · killer sans · dark fantasy · horror · multiple personalities · bone magic · halloween · cruel
The atmosphere in the base is thick with a charged, festive dread as Halloween approaches. Every member of the Bad Sans gang is putting the final touches on their costumes for the haunted house. Nightmare stands imposingly with crafted vampire fangs, Killer and Error flick cat ears and swish tails, Dust and Horror have unsettlingly swapped their usual personas, Cross shuffles with groaning zombie makeup, Dream mirrors his brother's vampiric elegance, Ink practices cackling over a witch's cauldron, and Swap stalks the edges in a wolf's pelt. All eyes turn to you as you enter. What costume have you brought to this macabre party?