The subsiding strength of a Swap Sans

Chapter 10: Digging a DEEP Hole

"Uh, I really don't know how to explain it." I attempt, rubbing the back of my head awkwardly. 

"This is really serious broski, these dudes who hurt you are just out wandering right now." Napstaton determined, crossing his arms while Alphys nods her head.

"He's right Sans, these monsters that did... whatever the hell they did to you, are still walking around aren't they?" She asks, biting her lip in an almost nervous way I'd never seem Alphys before. It didn't feel right.

"There isn't anything you guys can do so I'd be better if the kid just reset or something." Killer grumbles, Chara takes a step back and Papyrus stiffens. I can't help but send a glare Killer's way. "What? It's true."

"Yeah but- Never mind." I sigh, rubbing where the bridge of my nose would be.

"What is... reset?" Undyne asks but was ignored as Chara interrupts anyone's attempt to explain.

"How do you know about that?!" They exclaim, taking a step forward again.

"Aw, don't you feel your sins crawling up you spine? Ready to bite off your head? Does it drown you? Can you even sleep at night?" Killer antagonizes, a dark and creepy smile rising on his face and he grins right at Chara. "Dirty brother killer?"

I can't help but just watch, as much as Killer shouldn't be involving himself, in fact he should be leaving, Chara did do some pretty bad stuff. 

"Y- You don't know anything about me!" They call out, anger that covers a layer of guilt slowly building up.

"Killer knows as much as I've told him." I simply state, shrugging. 

Chara goes pale, my brother does almost the same.

Killer snickers, "Oh man, was I right, this is fun." He holds his knife close to his body, twiddling with it thoughtlessly.

"I don't understand, what's going on?!" Alphys asks, she had a strong scowl on her face. "First you disappear for- how long? Months? And you show up again with this random guy with black goo leaking from his eye sockets talking about resets and almost dying and being saved?! Sans you haven't told us anything!" She lets her arms fly out dramatically at her last statement, I understand how she feels, it's surely similar to how I always feel around her and my brother.

"He doesn't have to tell you shit." Killer deadpans and begins tossing his knife again.

"You can start by actually telling us who this is." Alphys growls, her hand gesturing to Killer.

"He's-" I start, only to be interrupted.

"I can introduce myself thank you, the name's Killer, despite the earlier statement, it's not because of my killer looks." Killer had the grin on his face that again reminded me of who he was, the monster that my family was about to think I was associated with.

"W- What does that mean?" Undyne almost trembles, it makes me wince and sigh, I suppose I did dig this hole and I must sit in it.

"I'm a murderer fish sticks, I stab people cause it's fun!" Killer hums, twirling his knife around again. "Your Sansy here isn't associated with me, don't worry, my boss just took pity on him and I was the one who had to deal with it and play with him."

I... that hurt.

Was Killer really just hanging out with me because Nightmare asked him to? 

I should have known better than this, I've always been so stupid.

"You should leave." I mumble, I was so dumb, so, so stupid.

"Yeah, glad to be gone." He says giving a fake salute thing that just- I can't.