Sans looked on impassively as a robot of confusing gender squared off against a child of a similarly confusing gender. He could tell Mettaton was doomed. One only had to look at the grey dust coating the kids shoes to know that. some of that dust would belong to Undyne. To the voice behind the door. To Papyrus. And even if the robot did win, Frisk- well, Chara, would just win next time. Or next time. Or next time. Or-

Sighing, Sans turned away, walking through the doorway.

._.

And emerging in the Kings garden. Asgore turned from his flowers at the sight of the skeleton. "Howdy! Sans, right? Been a while since I've seen you, would you-"

"Get the souls."

"I... What?"

Sans levelled a stare at the goat-like monster. "Get. the souls. Absorb one. Leave."

Asgore frowned. "But why? Undyne tells me that a human child is approaching-"

"Undyne's dead." Sans commented. "The human has a Level Of ViolEnce well into the double digits."

Asgore frowned. "But to do that, they'd have to kill..."

Sans nodded, slowly.

"Well..." Asgore gulped. "I suppose we'll have to make a final stand here-"

"NO!" Asgore almost recoiled at the anger in Sans' voice, the blue fire in his right eye tinting the flowers nearby. "You would die. I would maybe kill her, I'm the only one who can kill her reliably, but she'd just kill me next time."

"I...Don't..."

Sans sighed. "I hate having to explain this... It's the kid's determination. If you manage to kill her, she just goes back to before the fight and try again. And again. As many times as she has to to win."

Asgore blinked. "Then... What do we do?"

Sans closed his eyes. "One human soul isn't enough to get through the barrier, right?"

"No, it takes a human soul and a monster sou..."

"Or more than one human soul." Sans reopened his eyes. "You're the only other monster in here who's soul will last long enough to be absorbed. Take the six human souls, absorb one, and leave with the rest. At least that way, the kid won't kill the human race as well."

Asgore looked in confusion at the short skeleton before him. "Are you sure? It isn't like you to be this serious."

Sans just shrugged. "Heh. Guess watching your world die (again) has a way of killing the mood. Souls. Now."

Sighing, Asgore flicked a finger, seven containers appearing beside him, one of them empty. Sans nodded. "Hey, leave me one, wouldja? I'd really like to not sacrifice myself if at all possible."

Asgore nodded quickly. "Yeah, of course! You can go first of you want!"

At Sans' blank look, he sighed and turned back to the souls. He hovered in front of the blue one, recalling the slumped form he had seen carried over Undyne's triumphant back. He gulped and turned to another, the yellow, the sight of the child's body splitting open beneath his spear flashing before his eyes...

Killed by Mettaton with his human exterminator protocols...

Trampled by a gang of monsters in Snowdin...

"I can't."

"What?"

Asgore could positively hear Sans' eyes turn black. "I...I killed these children... Wrapped their dead bodies and stored their souls in casks... Just for a change of scenery, I..."

He turned to Sans who was watching him, completely still. "I can't do this to them. Can't I stay here? Please?"

Sans stood there impassively for a moment, before, quietly, "Of course."

Sans flicked a finger and a veritable forest of bones erupted from beneath the King, trapping him as well as causing significant damage. "Wh...what?"

Sans shrugged, one eye flickering blue-orange. He gestures, and a pair of Gaster Blasters formed behind him. "For a King, you're a Royal screw up, huh? If you stay, and stay alive, Chara kills another species. Choose."

Asgore coughed, the bleed damage making it difficult to breathe. "I...I can't!"

Sans shrugged, the Gaster Blasters opened their mouths...

And a circle of pellets collided with Asgore, grinding him into dust, a pale white heart floating above the mound.

"Well howdy! What am I gonna do with all these souls?"

._.

Purposefully, Chara (frisk was there too, spectating really) strode out of the room, real knife FINALLY clutched in their hands. Sans hadn't been in the judgement hall. That was weird. Then again, he probably thought he would hold out against her longer with Asgore's help. Figuratively longer, of course. It would be the same loop of time reset each time they lost. And this time, Chara wasn't going to let frisk launch a true reset she was distracted. even if Chara had her soul, frisk had still managed to screw her over. But this time, Chara was going to get those six souls when she were done KILLING EVERYTHING and escape into the humans' world. And then...

Suddenly, Flowey popped up beside her. Something seemed... Off about the plant. Almost luminescent. "Howdy! Sans is waiting for you before the portal. I'd try to fight him, but, well, that bonehead terrifies me." Chara turned to him and raised an eyebrow, giving that look that terrified the flower. He had absorbed the six souls, hadn't he? Idiot. Nothing could stop her. Even if he could start messing with the saves with that much power, he still couldn't stop her coming back. Again and again...

Flowey had popped away again by the time she shoved open the doors, only to see Sans stood there, rippling with power. She was filled with determination, the new save establishing itself, and she rushed at him, knife outstretched-

And bounced off.

Then she looked around. A pile of dust on the flowerbed, three empty canisters on the ground, and four, with souls inside, beside Flowey and Sans. Both of whom, Chara now realised, were grinning at her from the other side of the barrier. She let out a primal yell and began throwing herself against the strange wall with all her strength. It wasn't enough. Sans chucked, cracking his neck. "Hate to put a Block on your progress, kid, so how about I stop being a Barrier to your learning and tell you what's up?"

Inside the kid, Chara was suffering a breakdown while Frisk was in stitches laughing.

"Ya see, I wanted a soul." Flowey stated, bobbing from side to side. "'Course I'd rather have six, or six dozen, but where you're concerned, I'll settle for sharing if it means, well, not death. Didja really think I wouldn't remember what you did?

Ya pal betraying-"

"Brother killing-"

"Murderer."

Chara couldn't think straight. "You got through... How did you get through? I'LL KILL YOU!"

Unabashed by her rage, Sans continued his monologue. "Well, Flowey wanted a soul, and I'd hate to Get In The Way of his dreams, so I let him have old sentimental Asgore's. Kind of a reality check for his morality."

"So we both nabbed a human soul, grabbed the spares, and waltzed through the barrier!"

Chara panted, slowly. "I will reset." She growled. "I will kill everyone. So you'll do this again. So i'll commit genocide again, and again. Until one day, I won't. And maybe, the third time i do that, you'll believe it's Frisk. And I'll proceed to slaughter everyone you care about, and you won't be able to stop me again."

Sans leaned forwards, his face tantalisingly close to the barrier. "Well then. I guess you'd better hop to it. If it takes you too long, a Frisky little kid just might come and give you a bad time."

Chara held his glowing blue eyes gaze for several seconds before blinking and looking away. "I'm gonna go kill that stupid lizard miner in waterfall." She muttered, stalking off.

Sans waited a good five minutes before sighing in relief. Flowey raised an eyebrow. "What do we do now? Sans? Smiley trash bag? Did we win?"

Sans turned around, and began walking towards the exit. "She can still reset back to when she first came in here. We haven't won."

Flowey vanished into the floor, reappearing in front of the leaving skeleton. "So...what do we do?"

Sans walked out into the overworld and looked out over the landscape. Determination rolled off him in waves, the blue human soul now within him providing encouragement. "We watch the sunrise. We try not to turn into giant scary monster things because of the extra soul power. And we wait for Chara to reset. There has to be some way to stop her. At least we've got forever to think about it."

Flowey nodded. "I'm not used to this empathy anymore, but...its kinda sad that we're the only ones who'll remember this. For everyone else, it will be such a surprise every single time when a human turns up. Then kills them, gains LOVE from them... Frisks them for money? Eh?"

Sans looked at the flower. And grinned. "Ya know, I almost regret killing you. Heck, if this works, I might Leaf you alive."

"Ow."

"I'm serious. You could get back to your Roots."

"Please stop."

"I mean, you could get a job, be a trader, a Petal-ler of goods-"

"Weak!"

"Maybe get in a Blossoming romance-"

"Gaster Blaster me, right now. Or yourself."

"Heck, you and frisk could be best-"

And the world reset.

So when i was going through Genocide, i thought: Why is Sans just waiting in the hall? He knows Frisk/Chara'll kill him eventually, and she's just looping the same time segment. So i started thinking: How do thy actually stop someone like that? Well, read the next chapter, and you'll find my other idea. Review if you have your own idea, or if you want to say anything. See y'all!