[So, I don't know if anyone has done this, but I have an idea for an AU.]
Looptale.
Sans watches the sunset, mildly bored.
He's also terrified. The kid's going to reset right.... About....
"SANS! WAKE UP! YOU'RE GOING TO BE LATE FOR SENTRY DUTY!"
Sans groans and sits up, rubbing the sleep from his eyesockets. They did it again. He was going to KILL them. Just when he thought he would finally get his happy ending.
No, THEIR happy ending.
Sans could never be happy, even if they were freed. All those memories. All those genocide runs.
They would haunt him until he dusted.
Frisk keeps taking it away from all of them. Of course, the others don't remember, but he does.
Every.
Single.
Timeline.
Nothing he does matters. The world revolves around the kid.
He's seen at least a thousand of those sunsets.
He gave up counting at 78.
After all, nothing he does will have any impact. The kid could just reset.
"SANS, GET DOWN HERE OR I'M COMING UP TO GET YOU!"
Papyrus.
He's seen Papyrus die more times than the sunset. It kills him inside, every day. He can't even look at his younger brother without seeing him turn to dust.
Papyrus starts stomping up the stairs, his footsteps sending tremors through the house. Sans' bedroom door suddenly slams open, revealing a lanky skeleton in a superhero outfit.
"COME ON, SANS! DON'T BE A LAZY BONES!" Papyrus exclaims, picking up Sans like he would a fold up chair.
"mmmm" Sans groaned, trying to pretend he'd actually been sleeping for the past eight hours.
"Five more minutes, bro. You know I like to sleep in ulna time."
"UGH!" Papyrus whined, stamping his foot. "SANS! IT'S TOO EARLY FOR PUNS. CAN'T YOU GIVE THEM A REST? "
"c'mon paps. i've got a femur, and i promise they've gotten better. "
Papyrus let out a sound that sounded like a cross between a scream, whine, and annoyed groan.
Sans smiled as Papyrus marched them both down the stairs and out of their house into Snowdin. That was less walking he had to do.
The sound of snow crunching beneath his brother's shoe was relaxing enough to let him drift in and out of consciousness as Papyrus starts his trek towards Sans' sentry station.
---
Papyrus sets his older brother down into the snow, and watches as he topples over and sinks into the icy ground.
“bro!” Sans squeals as he is enveloped in freezing cold snow.
“snow need to be so cold!”
Papyrus stamps his foot, irritated.
“UGH. BROTHER, I HAVE TO GO RECALIBRATE MY PUZZLES. DON’T FALL ASLEEP IN MY ABSENCE.”
“alright. i guess icy you later then.”
Sans’ mouth turns up at the corners as Papyrus stomps off, apparently extremely upset with him. Sans was satsfied, after all, he’d be able to speak with the kid.
A L O N E.
As if on cue, he spots the child nervously making their way forward. They should be nervous, after all, they have to know something’s up if Sans doesn’t even bother following them.
Their choppy brown hair sways in the non-existent wind as their boots sink into the thick, white snow, snowflakes staining their pink-and-blue striped sweater.
Sans turns around very slowly, addressing the 12 year old.
“f r i s k.”
[End of chapter one.]