1 - 20 of 437 Works in Sans/Underfell Sans (Undertale)
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I am hosting a DTIYS challenge for passing 10k hits!
More info on CH19(As of 28/7/25 the first chapter has been rewritten to improve the flow and clarity of the story.)
(I will continue to edit earlier chapters bit by bit. When I'm done, I will announce it in later chapters.)
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Error's done. Fate has been in control of his life for too long. He doesn't want to do this forced job anymore. No more. So he takes a risk.A risk that eventually makes Error terrified of what's to come. More for the ones he calls family than for himself.
Ink realises he's not the only one suffering from fate. He's just as trapped as Error is in this forced job. So Ink does the best thing he could think of. He helps. Well... That leads to more problems for both of them.
Fate will never go easy on them again.
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FGOD Error and Ink are taken by Fate because Error broke the rules, and Ink discovered that Error is experiencing the same struggles as him. The multiverse Sanses must rescue them.
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This series will be split into two parts:
Part 1: Entangled in Ink and Strings 18/?
Part 2: Stitched up at last(FGOD error belongs to harrish6)
Series
- Part 1 of Free at last
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Sans goes to pay his dues at the library but ends up flirting with the librarian instead.
- Language:
- English
- Words:
- 952
- Chapters:
- 1/1
- Kudos:
- 5
- Hits:
- 20
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Sans was expecting a lot of things when he and his brother faceplanted into a familiar-but-not carpet.
His brother finding his soulmate was not one of them.
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A new series for Kustard week 2025.
Prompt: blue and red makes purple
Ever heard of a yandere bitty? How about two?
Series
- Part 8 of Kustard week
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Childhood friends Sans and Red are thrust back together after years apart, igniting old feelings and buried fears.
A surface AU.
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Maybe one day (NEW VER.) by me_paina for WrittenKinzy18, Clichely
Fandoms: Undertale (Video Game)
18 Sep 2025
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(Note: Reading ClicheAly's Murder to Dust and An Alternate Turn of Events and WrittenKinzy18's Winged AU series will 100% make this fic more enjoyable, but you don't have too. This could be read as a standalone.)
This is only going to get worse before it gets better, and well... Lets pray he won't find a way here because...
No one would survive his massacre.
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ATE Dust accidentally got transported to the winged universe.
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Just a tip to you all, this story will have violence and it may disturb some audiences.If you haven't read ClicheAly's writing, you won't know how gruesome some parts are and you won't know anything about this Dust or his AU, so I highly suggest that you read Murder to Dust and An Alternate Turn of Events before you read mine.
It is also good to know that this is taking place in the Winged Multiverse, so I suggest you read WrittenKinzy18 stories and series.
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4/?(ATE multiverse belongs to ClicheAly)
(Winged multiverse belongs to WrittenKinzy18)
(Drawing by me (Me Paina))
(Undertale by toby fox)Series
- Part 2 of CROSSOVER BETWEEN ATE AND WINGED AU
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Justice is BLIND to evil doing UNSPEAKable acts of kindness by Anjel_X for silverryu25
Fandoms: Undertale (Video Game)
15 Sep 2025
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When a horrible event happens to one unfortunate AU, their saviors end up being the last people one would expect...
Why would the bad guys do such an act of kindness... and is there more to it than that... they'll just have to hope a certain Trio doesn't give them a Bad Time™ in the process...A Kustard fic with an unexpected twist in the form of a Nightmarish poly of miscreants
My Secret Santa Gyftfic for fellow Kustard and pun lover, the SANSational Silverryu!
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He was gone. No warning, no alert, only taken.
Red is scared, Sans feels the darkness closing in.
It's done nothing but rain since he went missing.
Series
- Part 15 of Typeface: sans-serif
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Red Bones (Uf!Sans) won a scholarship at the St. Wendell Ebott University, a secluded University in Maine, and goes abroad to study at the Tōkyō Rika Daigaku (Tokyo University of Science) to become a Bachelor of Science. With his late father’s last savings, he flies to Tokyo and takes residence there.
Sans Serif (Ut!Sans) is offered a position as a teacher at the prestigious Tokyo University of Science. Having won a Nobel Prize in Physics 20XX for his findings in quantum physics, studies of multiple alternate universes and The Void. He is ready to impart his wisdom to the masses as a part time professor.
What happens when these two collide?
Drama unfolds!
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A collection of Undertale UTMV one-shots and small drabbles that I don't want to make entire stories for.
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No one has heard from nightmare’s gang for some time. Some time as in years. No one knows what they’re doing or what they’re planning. So what’s the problem? There’s no destruction all over AUs, and people are able to feel negativity without nightmare barging in to commit crimes. Dream felt like there’s something wrong though. Together with Ink and Blue(Swap), they investigate what’s really happening. Unfortunately, they will regret that..
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This takes place in a post Underfell King Papyrus ending.
Struck by under population, King Papyrus makes it law that all monsters left alive by the murderous little human have to procreate. This leaves Fell!Sans and The King himself in a tight spot. There are no female skeletons left in the whole Underground and both skeletons are sure they are the last of their species. Fell!Sans proposes something. With the help of the first Royal Scientist's machine to travel to other universes, he will find mates for breeding purposes.
Tale!Sans is having his first sub heat as a female. This happens when there are only males left and the strongest one undergoes a gender swap. He knows this means Papyrus will have to be his mate.
That won't do. They are brothers, for the Angel's sake! So he does what he does best, HE RUNS.
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Frisk absorbs Sans' soul after an unintentional genocide run. In her grief, she resets to try to fix it and make everything right. However, things don't go as planned and she ends up in a violent version of the Underground. With Sans stuck in her head, she now has his magic to help them survive and escape. But Frisk is committed to sparing. It will be difficult to spare when everyone here wants to kill her. What will she and Sans do?
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When the Kusted Rots, will the recipe stay the same. by MangaanadAnima for silverryu25
Fandoms: Undertale (Video Game)
21 Jun 2025
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Undertale and Underfell meet when most of the Aus gather together let see what happens when they meet after the system goes down.
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Sans is a pretty calm skeleton, then what, or more precisely, who made him lose his temper?
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Mermaids are the social butterflies of the sea, living in sunny, shallow water together with the rest of their school. On the other end of the spectrum, meroctopuses are violent, antisocial fucks who like the cold and the dark, and who basically kill any competing predator they see.
But they aren’t stupid.
Red is proof of that, using his traps to hunt for food and saving his energy to ward off predators. So, how does he react when he finds the laziest creature in the ocean stealing his catch?
Bribe him with more food in exchange for peaceful company, of course! The ocean is fucking lonely for giant predatory mer!
Red unwittingly gets saved by those peaceful conversations. Apparently even a cold-hearted predator can fall in love. And from there, their family keeps growing as more lost souls are saved by the siren’s call that sings of peace, love, and family, no matter how terrible of a monster you were in the past.
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Red has something he wants to show Sans.
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It's been four months since the whole world tilted and spun out under Sans, dropping him into the snow in front of a very tall skeleton.
Four months, as it turns out, is a very long time.
Series
- Part 2 of no way off the hamster wheel
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The Third Secret Option by Embrace_the_Deep (DefinitelyNotABee)
Fandoms: Undertale (Video Game)
14 Mar 2025
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A collection of snippets, add-ons, and what-if side stories for Kiss Me, Kill Me (and a Secret Third Option).
NSFW Chapters will be marked with an asterisk*, just in case.
Series
- Part 2 of The Third Secret Option
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Why write something positive when you can write about your favorite ship when the other one is dead? I feel like this idea has been used many times before but I wanted to try it myself.
I wrote this to practice and I'll probably write a lot of one shots to improve my writing.