He hadn't seen the "friendliness pellets" that had struck him in fury and denial from behind. But he'd heard a loud, hateful, torn scream. A mixture of denial, of confusion and anger.
Despite everything, Flowey had, deep down, still felt a semblance of caring for his dear friend Chara, who now possessed an innocent form. And seeing her tossing the knife away...crying in front of the skeletal comedian that was Sans...it had made Flowey think only one thing. Chara had just been playing this whole time. She never would have hurt him. It'd just been part of the game.
But now she'd been killed. Sans had let the posessed form of young Frisk get close...and then impaled the child through the back with a smirk and a cry of "GEEEEEEET DUNKED ON!"
And with that, Sans's own life had ended, Frisk flopping forth into a pile of dust, hearing Chara screaming in a mixture of anger and joy, satisified at least in the knowledge that if she went down...she took everyone else with her.
And then there he was. Sans now stood before large, golden, pearly gates on a plain of fluffy white clouds, as an expanse of a thousand stars in a beautiful starlight sky flickered high above him. An angel with deeply piercing green eyes was standing next to a man in a white beard and white robe, the green-and-gold-clothed angel whispering to the white-bearded man behind the ivory podium he stood at, guarding the entrance into what Sans knew could only be...
"this is...is this it? i'm in Heaven? really?" he asked, tilting his head to the side, looking rather impressed as soft music drifted out from behind the gates, and milky galaxies twisted high above his skeletal cranium. Smiling happily, he walked towards the podium, not seeing the other people waiting behind him who were all nervously rubbing the back of their necks, or muttering to each other. "heya. the name's Sans. sans the skeleton. can I go in?"
"I'm sorry, but no." Saint Peter said as he sighed, holding out the enormous book that he was writing on behind the podium. "I just got very clear instruction, even for you. And Mr. Sans, I'm sorry to say this, but neither you NOR your friends can go in. We have much to discuss."
"whuh?" Sans turned around, eyes widening. A fish-like woman monster with red hair, a dinosaur-esque monster in a labcoat, a goat-like monster with a lovely white and purple robe and soft blue eyes, a faintly spectral figure that looked very much like a flamboyant robot...
WOOP. And just like that, as if snapping into existence, there was a large, bearded goat-like monster with a crown on his head who felt over his body, cringing. "That was...why did that flower do that?! How...how strange."
"lil' bastard got you too, huh?" Sans sighed before the angel that had been speaking to St. Peter whacked him over his head. "ow!"
"No SWEARING. This is Heaven. And you need to make a good impression! If you want to get in, you must argue your case before the Heavenly court, and I shan't have my clients ruining their chances by being argumentative vulgarians!" The angel insisted in a voice that was both faintly childlike, yet so very, very old.
"why a court case? how come we can't go in?"
"You can't think of at least...oh...SIX good reasons why you can't?" The angel inquired, Sans flinching. In an instant, it all came flooding back. A hundred different timelines, a hundred different possibilities was all being smushed into his brain as his friends quietly watched him process what THEY'D had to process, Asgore soon getting the same information through his crowned head as he hung it in shame.
Six Human kids. All dead. Their souls ripped from them by the monsters to break the barrier and free them from the Underground to commit genocide against humanity for what had been done over a millenia ago.
"...oh." Sans mumbled. "but-but look, we were desperate to get out. we needed those kids's souls to-"
"It's not YOUR job to decide what happens to a person's soul. It's theirs and God's alone." St. Peter warned him. "And that foolish "ends justify the means" mindset is the very thing that led your people to be sealed away Underground. For the humans, their ends of keeping their people safe from monsters who regularly stole human souls to gain power justified the means of exiling you all away after a horrific and long, bloody series of battles. As your eldest brother Gaster can attest to."
Sans flinched. Oh, geez. So that's why his brother had had those lines over his face. He'd heard rumors, of course. That lines running from your eyes meant you'd absorbed a human soul, obtained what they had: DETERMINATION. But he'd never believed them.
But now...
"The good news is that someone is willing to speak on your behalf." The angel offered. "We've got a wonderful witness for the defense. Though the prosecution is...considerable. We'll have a hundred possibilities to stack up against. A hundred ways things could and did play out. Every possibility will be on display, and you must convince the Heavenly Host that you deserve a second chance."
"Wait a minute." Undyne suddenly remarked, the fish-woman speaking up. "Something isn't adding up. You say we all gotta answer for everything we did in all these possible timelines and junk, but surely we didn't ALL do awful things in EVERY single one."
"There's only one of you that DIDN'T kill anyone and who's morals remained consistant and noble from the start. One who truly did deserve heavenly bliss." St. Peter admitted, their angelic defense lawyer nodding as he jabbed his thumb at a small part of the gate that was down a ways, and they all turned to see Papyrus the skeleton in his jogging outfit, racing alongside a large plethroa of angels who were all running along a golden pathway.
"OKAY, BOYS AND GIRLS! WIGGLE THAT FLAB! TIME TO JOG 100 LAPS, HOOTING ABOUT HOW GREAT THINGS ARE! A ONE! A TWO! A THREE!"
"Everything is awesooooome! Everything is cool when you're part of a team!" The angels all sang out, racing by the gate with Papyrus as Sans blinked stupidly for a moment, then shrugged.
"...yeah. makes sense."