Spared

Sans heard their footsteps through the corridor a little while before they emerged from the shadows. Their expression was blank, but their clothes were dusty. Countless monsters had died by their hands. And Sans knew he was next.

"you've been busy, huh?" the skeleton said when the human approached. They smiled when they heard that. It was a big grin that let Sans know perfectly little scared they were of him. Why would they, anyway? With the SAVE power they could fight as many times as they wanted against him. As many times as they needed. Sans tensed, completely aware of the situation. He just couldn't win. Not unless they gave up.

But that didn't meant he wasn't going to try. He couldn't allow them to pass. If they did... well, the world was over. Everything would be over. Giving up wasn't an option for him anymore.

"sorry, old lady. this is why i never make promises."

Sans attacked before they could react. The human had been approaching him, and the further he was from them, the better. Sans was perfectly conscious of how physically weak he was, and how full of hate the human was. The skeleton wouldn't probably survive much more than one hit from that knife.

The human was stupidly agile and avoided every attack. Their grin never disappeared. They jumped and run around, getting closer to the skeleton despite all the bones Sans was throwing and the blasters he was shooting at them. The blue magic didn't seem to affect them much either. That kid was too good, and he was getting closer fast. And Sans was so concentrated in controlling the dangerous floating skulls he didn't notice until the kid was right in front of them, ready to stab him and with a horrible smile in their face. Their eyes were red for a split second.

And then, their hole expression changed and was substituted by a scared one. Both the human and the skeleton froze in surprise.

Sans reacted faster, what practically saved his live. He teleported to the other side of the room in a blink. He watched the human from safety, how he started trembling for some reason a few seconds. Then they seemed to return back to normal, and started running towards the skeleton.

But the he had already seen their expression. It was like they had turned into a completely different person for one second. Someone who was terribly scared and who didn't want to kill. Someone who couldn't control their actions. Someone —Sans was suddenly sure of that— he knew. Sans felt decrease his will to fight, his attacks growing slower, and was forced to teleport again to avoid another stab from the human. And he saw the grin that kid had in their face. They knew. All of a sudden, the skeleton wasn't sure about who of them was having a bad time anymore.

The human started running towards him again, and while the skeleton got ready to attack and defend himself, the weirdest thing happened. The kid tripped. They fell on the golden floor and their knife slide a few meters. But Sans was observant, and he saw that the human hadn't simply stumbled. Their legs had entangled themselves in such a weird way it could only had been on purpose. The skeleton knew it could cost him his life, but stopped the attack. Something strange was happening.

The human got up and run towards the knife, taking it from the ground. They smiled at Sans with a glint of red in their eyes. And their free hand gripped the knife and tried to take it while the kid's face changed again. They looked terrified. The free hand seemed to win, as it took the knife. The human threw it trough one of the golden windows. The shatter sound seemed to make them snap.

"I don't want to kill anyone!" they started shouting, falling onto their knees and grabbing their heir. They were crying. "Stop already! Get out of my head! GET OUT OF MY HEAD!"

Sans stared, unable to react, but with his suspicions confirmed. The kid was possessed. By what, he didn't know; but all the murdering seemed their fault. His friend —yes, that kid was his friend— would never do something like that.

"Kill me, Sans!" the shout startled the skeleton. Had he heard right? "Kill me! Before they can control my body again! Please!" the human was looking at him, crying and with a desperate expression in their face.

Sans stared back and approached the human slowly. They were shaking violently, and he could sometimes see an attempt of a smile that quickly disappeared behind more tears and despair. His friend was fighting, but he was losing.

"don't worry, Frisk. i got this" he kneeled next to the human.

They stared at him, almost as if they couldn't believe Sans had truly remembered their name. The skeleton hugged him and Frisk didn't resist.

"Hurry" Sans heard the human whisper between sobs "Before they... before they..."

"i know, kid. " the skeleton assured them. "i know."

Sans grabbed the human firmly, while he felt how almost all his ribs started dislocating, leaving the breastbone barely attached to a pair of them. The human screamed in pain while the bones perforated their torso and internal organs. They writhed in an unconscious reaction to get away from the pain, but Sans had a tight grip. He wouldn't let them go.

"shhh. 's okay, kid. the pain will go soon. don't worry." the skeleton tried to comfort them while softly stroking their head. The kid kept screaming in pain, choking on their own blood and tears, holding onto the skeleton's back with all the strength they had left. They felt Chara getting desperate to get away from the monster, but Frisk wouldn't let them win the control of their body. And they trusted Sans wouldn't let them go either, even if that meant their death. And Frisk finally felt the other human's presence disappear.

Frisk relaxed despite the pain. They had a sad smile on their face and blood was falling from their mouth. They coughed more blood as they tried to speak, and they kept trying despite Sans telling them softly everything would be fine.

"So...rry... didn't want... kill... Papy..." they managed to say, while more tears started falling from their eyes. They chocked. "... anks... Sans..."

The skeleton didn't answer, and the human didn't say anything else. He was still hugging the kid. He wouldn't let them go. Frisk didn't say anything. They were dead. Sans didn't move.

The light filtered through the windows, making the place shine with a golden light, and their shadows darker on the bright floor.

His bones were red, soaked in blood. His face was damped, wet with tears.

Sans was so, so tired.