Betwixt and Between (UT!Sans x Reader x US! Papyrus)

Chapter 1 Familiar Faces

You woke up with a shuddering gasp, lungs giving firey protest at being forced to do their job. You shift, and let out a cry as waves of shooting pain enveloped your senses. Your vision is blurry, but you vaguely register the cold snow below you. You must be somewhere around Snowdin then... Wait what? Confusion rattled in your brain as you struggled to remember.

"Hold on... What's going on here?" asked a familiar voice. But... It sounded...strange, and the tone was tense and harsh. You shifted again to try and see the source of the voice, to be met with the sound of someone taking a few steps back.

"PAPYRUS I TOLD YOU NOT TO HURT THE HUMAN!" A voice shouted, sending more uneeded pain through your head. Once again the voice sounded familiar but wrong. And why would Papyrus hurt you? It didn't make sense, you were best friends. The confusion increased. You managed to sit up and your vision cleared enough to properly observe the scene in front of you.

A tall skeleton clad in an orange hoodie and a scowl was holding back a much smaller skeleton, who was dressed in grey with a blue scarf. The shorter one was looking back and forth between you and his brother, a very concerned expression twisting his otherwise adorable features.

"Sans, stay away from the human. " Papyrus ordered. Sans tried opening his mouth to argue but a stern look shut him down. You shifted uncomfortably, the pain all over bringing tears to your eyes from its intensity. Bad move. Papyrus's left eye flared orange as he sharply pulled Sans further away out of fear. Left... eye? You always had known Papyrus to manifest his magic in his right. It was Sans that had it in his left. And Sans was wearing armor? Something...was very not right. Was it a prank? It was a bit too much for one, and since when did Papyrus join in on those? It couldn't be a prank. A really realistic dream? But why did everything hurt?
You were pulled out of your confusion by Papyrus shifting a hand in your direction.

"I saw your soul shatter! You should have been forced to reset at least!" he growled at you. "What have you done?!"

"R-reset?"Your voice cracked out in a hoarse whisper. You had no idea what he was talking about. "I died??" You questioned anxiously.
They both looked stunned for a moment, but Papyrus regained his composure quickly, and looked angrier than ever. He flung a hand in your direction, and you barely manage to dodge five bones that would have impaled you in the chest.

"Don't act all innocent! Not after all the sins you've committed!" Sins? What had you done? You couldn't remember anything, and fear filled you to the point of incoherence as he flung another attack.
Fleeing the volley of bones, you dash away, out of Snowdin and down the forest path. You didn't think about where you were going, just trying to get away. You lost track of how long you ran. You ran until your lungs, already burning from previous punishment, felt like they were going to burst. You eventually started to slow down and the sharp cold began to bring back a sense of rationality. As you ran you started to notice piles of grey shimmering dust scattered along the way. You slow down to a stop knowing that piles of such a substance was a very bad sign.
Something or someone was killing monsters.
The thought chilled you to the core. You shivered, but not from the cold. You couldn't imagine someone wanting to hurt these people. They were- or at least you thought they were- your friends. Rubbing your arms, you took a step backwards and a sharp snap startled you, causing you to jump out of your skin. You looked around wildly and realized that you had stepped on a twig. Halfway through huffing out a sigh of relief, you noticed something that scared you more than anything had so far.
Your legs, feet, and hands were covered in the same silvery dust.

Someone was killing the monsters, and that someone was you.