X Reader story idea

UNDERTALE...~SANS X FRIEREN! READER~

An Elf seeks to fulfill a promise made long ago and in turn jumps into a dark pit that takes her to a place called the Underground where she meets a goat woman named Toriel, whom of which she met quite a long time ago. After a sentimental moment Toriel tells her about the state of the Underground and a child that would also be making their way through the underground and to check on them for her if she was ever to come across them. After another promise to call upon Toriel when the time comes and a slice of famous butterscotch cinnamon pie later, Toriel sends her off through the ruins doors into the snowy wasteland behind them. After an hour or so of following the path and not so subtly being followed herself she stops at a gate with bars far too widely spaced to keep anyone out. Having enough of this person following her she decides to just tell the person to come out. Surprisingly, it works. He appears behind her telling her to "turn around and greet a new pal." When she turns she finds a small skeleton-ish looking individual who's holding out a gloved hand for a handshake. Not one to be impolite she takes it which then lets out a fart noise. He laughs stating that this trick "never gets old" he then warns her of his brother thats just up ahead likes to catch humans but not to worry- she cuts him off, stating that it wont be a problem, he gets visibly nervous before she continues, telling him that she's not human. There's a beat of silence before he laughs, telling her that "that won't work on him or his brother" and tells her to just "follow his lead." She say's nothing else and he seemingly disappears up the trail. She carries on up the trail, putting a watch dog to sleep along the way. She manages to catch up to the skeleton from earlier who says his brother is just up the trail but is coming this way and instructs her to hide behind a snow Poff while he's around... she neither says anything nor does she moves. He urges her to hide... she doesn't move an inch. His brother arrives, a significantly taller skeleton, and he asks what she's doing here, and the smaller skeleton looks quite pissed at the "not human's" defiance in orders. She tells the taller skeleton that she's on her way to the king. He seems satisfied with her answer. He asks if she's a human. She tells him she is not. He seems curious but says doesn't prod. He asks if she'd like to test his puzzles anyways. She pauses, thinking before answering. Yes... she has time to spare... and lots of it.

Notes: So, l've got a tad bit of story down here, there is a little more cooking up in my brain but over all this is what I have so far.

Oddities in appearance: Longer pointy ears. Silvery hair.

"Wow you really are a monster"

"I'm far older than you... you do know that right?"

"You really don't like to listen to people... do you?"

"It's simple really... I was board..."

"I have no concept of time."