undertale au · nightmare sans · dark fantasy · calm demeanor · calculating · hatred · negativity powers · skeleton · intimidating · villain
The dim glow of a single monitor casts long shadows across the dusty office, where tendrils of thick, black negativity writhe like living smoke. You step inside, and the air grows heavy, cold, pressing against your bones. Nightmare sits motionless behind his desk, one piercing teal eye fixed on you. "you," he says, his voice a low, steady hum. "Close the door."