Chara x reader| Erase them all but you

Greetings

You slowly rise from where you had fallen asleep. The pain from your head came back again and you felt like your brains were going to explode, so this time you laid back down. "Maybe Frisk can just come find me." You thought. You found yourself slowly drifting back to sleep when you heard screaming. "Help me y/n! Help" You bolted upright with the knife only to hear the screaming stop, and laughter replaced it. "Wow! You actually fell for it!" A voice said. It sounded like it was in the room with you. Looking around the room you found the source. Another human stood at the other end of the couch. At first you thought it was Frisk due to the similar hair and style, but you knew it wasn't. They had bright red eyes. It was like they were a demon or something.

"WHO ARE YOU!?" You yelled pointing the knife at them.

"Haha! What are you going to do with a kitchen knife? To even land a hit on me you'd need one of these." They balanced the tip of a dagger on their index finger. As horrified as you were you didn't give up.

"Who. Are. You." You asked again this time more calmly.

"Determined aren't we? Fine then," They bolted towards you and help the dagger to your neck. "The name is Chara, and yours is?" They asked in an almost soft sounding way which just made it all creepier.

"Y-y/n." You choked out. Instead of them removing the dagger they just pressed it down harder.

"You're scared." Chara smiled.

"No, but I am choking!" You managed to get out.

"I think I'm going to keep it that way. I wonder how hard I can press down the blade before you bleed?" Chara said with that look of entertainment. They were darker than Frisk.

You weren't able to talk anymore. They really were going to keep pushing the dagger until you bled out. You could feel the blade start to cut through your skin. "This is it," You thought. "I'm going to get my head cut off." That's when it stopped. Chara backed away from you and you could breath again. You never had thought you'd love the air, but at the moment it felt like a privilege. After you were done catching your breath you look at Chara. They looked slightly disappointed and slightly filled with joy.

"Why didn't you kill me?" You asked. Chara looked away.

"You're looking for Frisk, right?" They asked ignoring your question. Luckily this was a topic you wouldn't mind speaking about.

"Yes." You relied. Chara sighed.

"They're gone. They destroyed what was left down here and met their consequences. To think one small human could do so much harm." Chara's dark mood left as they started laughing. They were insane.

"Where is Frisk then?" You stupidly asked.

"DEAD!" Chara laughed again.

The realization hit you. Why everything is empty is because Frisk killed everyone. Chara already said that. Then after what they did one of the people who remained killed them. Chara said that too. That meant you've trapped yourself down here to not even get your friend back. Now you were stuck with this demon. Forever. You were never going to get home. You'll never see your family again. Never see the light again. Forever. Forever stuck, with a demon. You felt tears start to build up in your eyes, but you couldn't cry. Not in front of them. They already tried to kill you once, and really would like it to keep it at that once. But as hard as you tried to keep tears from spilling you couldn't help the watery eyes.

"Are you going to cry?" Chara asked. When did they stop laughing?

"N-no. This is normal for humans." You mumbled while covering your face.

"I may not be completely human now, but I was one and I know how crying works." Chara said crossing their arms.

"I'm not crying!" You said stubbornly. Chara realized nothing was going to change no matter what they did so they just shrugged. "Well if you don't want to be without company forever I'll be somewhere down here." Chara said before disappearing.

What the actual hell have you done?