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𝐓𝐇𝐄 𝐅𝐈𝐍𝐀𝐋 𝐃𝐑𝐀𝐅𝐓 ✧ 𝐁𝐀𝐃 𝐒𝐀𝐍𝐒𝐄𝐒 𝐗 𝐑𝐄𝐀𝐃𝐄𝐑 by chaesteria
Fandoms: Undertale (Video Game), Undertale AUs - Fandom
06 Feb 2026
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Remember the times you joked about "dying for your fictional crushes"?
Well, one chronically online, strawberry patterned pajama-clad Bad Sanses fangirl actually did—courtesy of a pixelated meme dog and what might be the universe's worst case of writer's block. Now, she's stuck in the Undertale multiverse with nothing but her AU knowledge, a deeply unserious System guide named Selene, and the terrifying realization that her beloved skeletons don't blush on first meeting.
They try to murder her.
Armed with terrible skeleton puns, niche references, and a soul that might be powered by sheer cringe, her new mission is clear: befriend the murderous skeletons, grind enough EXP to not die (again), and somehow stop the multiverse from collapsing-all while convincing a glitchy skeleton that she's not the weirdest thing he's seen today. (She is.)
It's a self-insert isekai where the only thing stronger than Determination is a fangirl's ability to ignore red flags.
[ I curse ao3 and its limited description. Uploaded this on Wattpad and Quotev as well! More active over there, this is my first released fic here :) ]
Published: February 1, 2026
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no matter what form, no matter what world, and no matter how many times, you'll fall back into familiarity with him as he will you.
(or one shots i've written from ambitious ideas for multi-chaptered fics i've had, most if not all tooth-rotting fluff with a slice-of-life touch to it. almost. mayhaps. perhaps a little bit of hurt/comfort sprinkled in.)
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Dust set his books down on the coffee table, managing to avoid collapsing. Where were the others? He looked around. The supply run had been mostly successful, but it had done a number on him. Dream had thrashed his ass, then Blue and Ink had handed it back to him neatly. There was also the problem of that human he had brought back…
This is my first fiction, so ignore it if it’s very cringe. Thanks!
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Choose Your Fighter by FandomWorld9728
Fandoms: Undertale (Video Game), Mafiatale - Fandom, Mafiafell - Fandom, Mafiaswap - Fandom
02 Feb 2026
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When your life gets turned upside down, you move to a Monster run city to for a fresh start. Against your will, mind you. On your way to your new job, you get saved by some very interesting skeletons...
Series
- Part 18 of Undertales Across the Multiverse
- Part 12 of Sans/Reader Fics
- Part 13 of Papyrus/Reader Fics
- Part 8 of Reader Inserts
- Part 2 of Morally Grey Fae
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Reader tries another attempt at a demon ritual in pursuit of helping their favorite demon skeletons.
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A special chapter from My Roommates From Another Universe, where our MC meets three other versions of herself.
Thank you to Battlemaiden for letting me use The House Next Door MC! I hope I did her justice
Series
- Part 2 of My Roommates From Another Universe!
- Part 17 of Undertales Across the Multiverse
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Magic Stones (Kidney stones? no.. but you're funny for that) by Certified_Lurker
Fandoms: Undertale (Video Game), Original Work
06 Dec 2025
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Magic sears through my veins, but I am determined to use every advantage I have.
Okay so.. pretty much... you have lore (and trauma).. these silly skeletons somehow get pulled into your universe and you have to find a way to get them home. Lots of action, lots of gay. They are gay for each other and for you.. maybe... at some point.. might take a while.
I do NOT consent for my work to be used for AI: prompts, teaching, character bots, or anything else related to AI.
Undertale belongs to uhhh Toby Fox or something idk..
IF YOU ARE MY FRIEND READING THIS- well howdy seeing you here- JUST PRETEND THIS ISNT ME, I AM A STRANGER TO YOU NOW
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Heat of the Moment by FandomWorld9728
Fandoms: Undertale (Video Game), Swapfell red - Fandom, Fellswap Gold - Fandom, Underswap - Fandom, Swapfell - Fandom
21 Nov 2025
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Being half demon and half human was hard. It affected your life in interesting and traumatic ways. Luckily for you, you had a pair of skeletons who would help you through whatever life threw your way. Only, things got more complicated when different versions of them began to show up.
Series
- Part 9 of Undertales Across the Multiverse
- Part 9 of Papyrus/Reader Fics
- Part 7 of Sans/Reader Fics
- Part 2 of Reader Inserts
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The bad guys get some needed relief.
Note: Horror and Killer have a pussy, while Dust has a cock.
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After playing undertale late at night and being sucked through your computer to that universe, you and your bone brigade have to figure out what it's like to live in a new world. And maybe try to get you home. If there's time.
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(Gender neutral reader x sans aus)
You’re just taking a walk one day, when you come across a huge hole in the ground. It would be weird if you tripped and fell in and met a bunch of skeletons or something…
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Here Comes the Bride by FandomWorld9728
Fandoms: Undertale (Video Game), Underfell - Fandom, Underswap - Fandom, Swapfell red - Fandom, Fellswap Gold - Fandom, Horrortale - Fandom, Underlust - Fandom, Echotale - Fandom
02 Nov 2025
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You were so excited to finally get married to your long time fiancé, only for him to leave you for another girl with nothing but a note. Lucky for you, your two best friends were there to help you through this rough patch of your life.
Arc 1: Chapter 1 - 18
Arc 2: Chapter 19 - ?Series
- Part 12 of Undertales Across the Multiverse
- Part 8 of Papyrus/Reader Fics
- Part 8 of Sans/Reader Fics
- Part 1 of Here Comes the Bride
- Part 3 of Reader Inserts
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Falling.
You were falling.
…Or were you?
You were weightless; both falling and floating; suspended in midair, nothing below your feet, but also no air flying past your face or whipping your hair around to tell of gravity’s play of hand.
And it was dark.
Suddenly, in the middle of the far distance, a white light appeared. With each passing second, it was growing bigger, bigger, and bigger still.
You realized, belatedly, that the light was drawing you in, tugging at your very being, and something about it was… awakening something within you.
The light grew closer, and your hope stirred.
You hadn’t wanted to die. You didn’t want to die.
You looked up into the light, and you reached out with everything you had.
With one final tug, the light pulled you into its embrace.
And just as tightly, you held on.
Series
- Part 1 of Falling Forward With You
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Your day starts off bad, and somehow, food only makes it worse.
Luckily, your boys are there to help pull you out of your slump.
Series
- Part 2 of Falling Forward With You
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Red wanted a drink, not a human. All he needed was one damn night away from Sans' smug comments, Edge's lectures, and the constant chaos of trying to fix the machine that yanked half a dozen alternate versions of himself and his brother into one reality. Instead, he found you- jaded, mouthy, and entirely too good at pushing his buttons.
[Sans and Papyrus x gender neutral Reader but Red x Reader main]
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She thought she had grown used to life with eight eccentric skeletons for neighbors, but when her neighbors asked her for a huge favor, she imagined that she would be babysitting the pets or watching the house while they went on vacation.. What she wasn't expecting was to have even more of said skeletons move into her house with her, each one more chaotic than the last.
[Eventual All Sans (and maybe some Papyrus) x she/her Reader with some random OC ones and some from other AUs]
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My Roommates From Another Universe by FandomWorld9728
Fandoms: Undertale (Video Game), Underfresh - Fandom, Fellswap Gold - Fandom, Inktale -Fandom, Dancetale - Fandom, Danceswap - Fandom, Dancefell - Fandom, Mafialust - Fandom
29 Sep 2025
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Your life has been complicated since you could remember. It only got more complicated when you were thrown into a completely different world and your new roommates happened to be different versions of the same two skeletons.
Series
- Part 14 of Undertales Across the Multiverse
- Part 11 of Papyrus/Reader Fics
- Part 10 of Sans/Reader Fics
- Part 5 of Reader Inserts
- Part 1 of My Roommates From Another Universe!
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After spending all your life in that damn facility, you come out of it and have no clue about anything, and you just want some friends and family, and maybe someone to love you.
My brother had given me the idea for this fic, and I really wanted to write it, hope y'all enjoy!
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Every place has its legends. Legends of monsters, ghouls, and anything that goes bump in the night. Almost everyone believes those legends as kids; when they grow up some tend to outgrow their beliefs. The legends surrounding Mt. Ebbott were just stories to tell kids so they wouldn’t wander too far. Until one day monsters came out from the mountain. Everyone was forced to believe in the legends then. Whether they were young or old.
The monsters were friendly despite their imprisonment. They just wanted their freedom and to coexist in harmony. Humanity was lucky in that regard. But the arrivals of the monsters made people begin to think. What other legends are real and will they be as friendly?
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Dying at the Altar by FandomWorld9728
Fandoms: Undertale (Video Game), Underfell - Fandom
22 Sep 2025
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What was supposed to be one of the best days of your life had became the worst. Your two best friends weren't here (even though they had promised), your fiancé had left you with nothing but a note explaining he had run away with his ex... Oh! And there was a zombie apocalypse you had to now fight your way through! At least you had something to take your frustrations out on. Now, you had to not only survive, but find your friends before something else did.
Series
- Part 13 of Undertales Across the Multiverse
- Part 10 of Papyrus/Reader Fics
- Part 9 of Sans/Reader Fics
- Part 2 of Here Comes the Bride
- Part 4 of Reader Inserts