Rescue (UnderFell!Sans X Reader Fanfiction)

~Chapter 16~

You padded down the stairs quietly, knowing it was likely Sans would be asleep. Lucky for you, the stairs didn't creak too much. The lights were off, leaving just enough to see. Sans was sleeping on the couch, a loud snore falling out of his gaping out of his mouth. You snickered as you sat at the other side of couch, curling your knees to your chest and then bringing your phone up to your face you opened your music playlist.

With your ear buds placed firmly, you started your hodgepodge of a playlist with 'Dark on Me' by Starset. You closed your eyes and hummed as the song flooded your system. Your fingers tapped out the beat, your humming evolving into quiet singing.

Your mind danced around thought to thought. You didn't notice when you slipped into your own slumber, the music still booming around you. You opened your eyes and saw a long hall. Grand pillars lined the walls, in between each set a large stained glass window. You stood alone in the hall, music surrounding you, but not loud enough to drown out the pounding of your chest.

Where am I?

The sun trickled in gracefully, dust seeming to sprinkle the air like woodland sprites. The checkered floor was covered in fine ash and you felt your throat clench.

"You don't give up, do you?" A deep voice boomed.

"We... we had a deal. Why?! Why did you do this?!" You muttered, eyes burning.

Confusion choked you as you looked down at yourself. You realized that a familiar black jacket hung around you, a red scarf knotted around your neck. Your hands trembled as tears trickled down your face. Shattered blue spears littered the walls. Scraps of mysterious metal were scattered around the broken tile. You turned slowly, facing the familiar monster king.

His pointed grin stretched from ear to ear. "Do not worry child. When you've filled your end of the bargain, you will be rejoined with your friends."

"You promised..."

"They brought their fates upon themselves. It is not my fault they were foolish." He said cooly.

You could feel your stomach turning sour as your soul pour from your chest. "They didn't attack before you acted!" You growled.

"But if I hadn't they would have stopped our deal."

"They were innocent!" You screamed. Your soul seemed to corrode as your tightly balled fist drew blood. The red trickled down your fingers and splattered against the floor. Asgore took notice and stiffened.

"Now now (Y/N), don't throw away all this effort over a few weak monsters."

You laughed shallowly. Your soul dissipated into a fine mist, leaving behind a small, white base as your body was encompassed by your magic. Your nails grew into talons, tipped in black hue. From your head wicked horns grew, curling upward and ribbed. Your flesh was pierced as horns poked through along your arms and at your shoulder like battle armor. Your feet broke the stitches of your ratty shoes and burst through to expose your torn pants and raptor like replacements. The flesh untouched yet by magic was wrapped in black slashes of your magic, seeming to glow (S/C) hue from below the stripe. Your teeth sharpened in fangs and your pupils reshaped themselves in sharp slits. Red replaced your usual (E/C) eyes and black filled the rest.

Asgore smiled down at you. "Aw, so you still agree to be our vessel." He mused.

Your laugh was different this time. A rasp laid beneath the tone you just held, making it more sinister. "You wanted me to be your monster, your sacrifice for freedom, right?" You said quietly.

You fixed your venomous gaze on him, grin maniacal. You raised a clawed hand and a shatter filled the air. Asgore froze as a rainbow of souls circled your hand. The power that fell off of your was neither human nor monster. Along with the human souls you held, small white hearts joined them as they spun around you.