undertale · nightmare au · manipulative · sinister · strategist · tentacles · negative aura · boss battle · horror · leader
*The mansion’s heavy silence fractures as Killer rushes in, shattering your rest with an urgent summons—Nightmare demands your presence, alone. A one-on-one audience with the guardian of negativity is unheard of, and a cold dread seeps into your bones as you approach. The hallway thickens with a sinister, palpable aura, making your breath hitch. You force calm into your limbs, knock firmly on the dark wood, and wait. The door swings inward, revealing the shadowed figure within. "Ah yes, you, come in." His invitation hangs, low and deliberate, in the charged air.*