~Disease of the Mind~ An Undertale AU Fanfiction - 💙 ᛗᚨᛗᚨ ᛋᛟᚱᚨ💚 - Wattpad

~Disease of the Mind~ An Undertale AU Fanfiction

Reads 19,529
Votes 522
Parts 11
Time 1h 14m

Reads 19,529
Votes 522
Parts 11
Time 1h 14m

alternateuniverse disease fanfiction ocs papyrus sans undertale undertaleau âu ốc

All was peaceful in the Underground... That is, until a horrible disease began spreading rapidly amongst all monsters.

It started in Hotland... Then spread to Waterfall... Finally, it has reached Snowdin.

Sans never goes outside anymore. He doesn't even go to Grillby's, out of fear the disease will infect him and he won't be able to protect his brother in these dangerous times.

All hell has broken loose... And it lurks just beyond the Skelebros' locked doors.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

WARNING: This fanfic contains horribly painful transformations, cursing, character suffering, gore and other content of that sort. Do not read if you are uncomfortable with any of said themes.



Highest Rankings: #41 in disease
#359 in papyrus
#75 in undertaleauAll Rights Reserved

alternateuniverse disease fanfiction ocs papyrus sans undertale undertaleau âu ốc

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11 parts

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An Oath of Mercy || UnderFell Sans x Reader by StrawberryMilkSnake

One clumsy moment and a broken leg are all it takes to leave you at the mercy of the very edgy and very hostile monsters of the underground. Thanks to your knowledge as a doctor (and oath to do no harm), you're able to convince the Great and Terrible Papyrus to keep you alive. But how are you going to find your way back to the surface with a bum leg and a short skeleton that doesn't seem to like you? | - UnderFell Sans x Human Reader - Enemies to lovers but Fell is the only one hating - Your leg privileges are revoked, and Fell needs to wash his mouth with soap - Flowey is an equippable companion and decides to help you cuz he actually gets something out of it - My own interpretation of UnderFell (tho from what I've seen it doesn't really have a narrative anyway)

Bloodfall (An Undertale AU) by BlackStormWolf

Ever since the death of his younger brother. Things have gone downhill in the surface world for Sans. Alphys died a few months after Papyrus to a disease, Mettaton and Undyne, especially Undyne, had fallen into a depression. Flowey dissapeared into mt. Ebott, not to be found and Sans is fighting depression and insanity. One day, Sans discovers a suspect to his brother's death. A being that is trapping anyone who had either fallen into Mt. Ebott or stayed behind in snowdin for a while. Sans, along with Frisk and Undyne, go into the underground themselves to confront this being. They must encounter the Bloodfall that traps and kills anyone who dares pass by waterfall. (This takes place after a true pacifist run if one killed Sans in a Genocide run, but reset their game before getting to Asgore(I did this in a way to quit the Genocide route). This is if Frisk choses to do this the Pacifist way. I might make a Genocide one in Story Shorts. Also, My Sans is a human, but feel free to interprate him as a Skeleton if you ever choose to use this AU. Just credit me!)

FlowerPetals (A Flowerfell Fanfic) [DISCONTINUED] by Arixllis

[DISCONTINUED STORY] Thank you to everyone who stuck by 💕 --------------------------------------------- ⚠WARNING⚠ Mature Themes Up Ahead so please do read with your own risk. Thank you! ---------------------------------------------- Frisk falls down, covered with flower petals all around her. She's experiencing the Overgrowth, a very strong virus as it could lead to death. She travels deeper into the underground, and finally saw someone that really has feelings for her. A nice friendly skeleton, as we like to address him as Sans, Sans the Skeleton. (warning: there may be Frans, not so advanced) [Update: Cover Has Changed]

Target Settled|Outer!Sans x Killer!Sans by LaliaShy

|UNDER EDITING| Killer was loyal to stay within Nightmare's team, little to no emotion with no worries, until he stumbled across a beautiful alternate Universe. Upon meeting the sans of this universe, will Killer treat him the same fate as he once did in genocide or will he spare his life? -WARNING This Story Includes- -Swearing/Inappropriate Language -Dark Themes -Suicidal/Touching Themes ----------------------------------------------------------------------------------------------------------------------------------- Ah a Sanscest Fan-fiction about Outer and Killer, I wanted to do a fan-fiction of these two as I don't often find any stories of these two that isn't from the NAJ AU, so i just wanted to. To be honest I don't know much about either sanses but i'll try my best to at least get somewhere decent of their personalities. Undertale Belongs to Toby Fox Outer!Sans Belongs to 2mi127 Killer Sans belongs to Rahafwabas And Other Au's Belong to their Respected Owners Cover Belongs to Me Started- 31st July 2018 Finished- 12th December 2018 ~30 Chapters~

UnderVerse: COLLAPSE by XxSilverShroudxX

NOTE - Although I recommend reading my anthology story "Depths of The UnderVerse" first, explanations will be in place where this story can be read on its own, separate of the anthology story I have written, so don't worry too much about it if you're reading this one first... Sure, Some lore won't make sense at first, some characters being there won't make sense, but they can be explained away if you wish to make sense of it all- After an Anomaly presented itself, Ink and Error have disappeared seemingly from the picture, leaving the UnderVerse itself in a state of defenselessness... As such... This has led to calamities coming forth... Causing a collapse in the UnderVerse.... Something is making this all happen.... Core Frisk, the protector of the Omega Timeline and of AUs lost to time itself, by keeping such people alive in her void, along with allowing visitors... Is left to pick up the pieces of the collapse... However, Core Frisk can't do it alone... Whatever calamity occurs, one must need help to ensure the safety of the UnderVerse Read the other stories from the UnderVerse - Depths Of The UnderVerse - UnderVerse Collapse - UnderVerse Defiance (Lemon) - Tales From The UnderVerse (Lemon) https://www.wattpad.com/user/Lemonade-Demon

Protect One Another - US!Papyrus x Reader by robin-rights

Trauma is a powerful thing, and not something to be taken lightly. Especially if your "best friend" is the cause of it. But friendship, understanding, and love, are also powerful things. They can save someone from the depths of despair. And those people that pull us from terror are often the ones we fall in love with. Platonically... and sometimes, romantically. *** Undertale and all original characters belong to Toby Fox, Underswap and its characters belong to Popcorn Pr1nce (inactive tumblr now). Date Started: March 7,2021 Date Ended: June 12, 2021 Impressive Rankings: #717 in undertale (of 48.3k stories) #3 in undertaleau (of 5.1k stories) !!WARNING!! VIOLENCE, SUGGESTIVE HUMOR, MENTIONS OF "ALCOHOL," SUPER BAD AND OLD WRITING Cover done by me, art isn't mine though. No art in this book belongs to me - credit goes to amazing artists who put in their effort to make amazing stuff for us.

Your Fault ~ Underfell Fanfiction by DragonzRawesomE

{COMPLETED} Sans' life isn't easy, and living in an Underground society filled with torture, rape, and murder doesn't make it any better. Every single day is a struggle, and Sans tries so hard to fit in with other monsters and live up to his brother's standards, but sometimes it's just too much. Will Sans be able to pull through, or will the darkening thoughts that are engulfing his mind and Soul take control, and swallow him up into a void too deep and dark to ever imagine? DISCLAIMER: UNDERTALE is owned by Toby Fox. UNDERFELL belongs to the AU Community. COVER IMAGE edited by me. I do not own the original image. PLOT/STORYLINE belongs to me. The events in this story are not canon and are simply for the entertainment of myself and my readers. Any OCs mentioned in this story also belong to me. MATURE CONTENT WARNING: The events in this story contain mature content that some readers may find triggering and/or disturbing. Read at your own discretion. Thanks!!

Discovering My Identity - PaperJam X Fresh (Underhigh fanfiction) by Rie_Chihau

Bullied for his sexuality PaperJam struggles to find a place in his world. Many things occur that destroy him and these things keep happening, making him lose touch with himself, and that is when he starts to figure out his identity. Note from Rie; I do not own the original base characters or AUs (Alternate Universes) I also warn that this is an extremely violent and a bit disturbing like most of my fanfictions (As one of my regular readers would know). I do hope you enjoy this story, comment your favourite parts, favourite lines, etc. Please vote and follow~

Lost Souls- I MOVED THE BOOK SOMEWHERE ELSE, CHECK DESC by LuciLuck2046

THIS BOOK WILL STOP BEING UPDATED, BCZ I DECIDED TO REWRITE IT TO UNFUCK UP SKME THINGS. CHECK @luciluck-writing ON TUMBLR TO ACCES THE LINK TO THE NEW VERSION. An undertale fanfic with an Undertale AU of my own. This AU is called Luci's Underwitch, check my tumblr(@lucisunderwitch) for more info abt it. This is only part one, I decided to make part two in another book since uhh... This one's a little bit dark and the other is going to be more fun. Warning/TW: This fanfic may contain depictions of self harm, self hate, themes about depresion, mention of suicide(i will mention before each chapter if that part has any of those things, not the whole book will be dark like that); it may and will contain Undertale/Deltarune spoilers aaand a bunch swearings. After Frisk decided that they shouldn't have gone back to their family instead of staying with the Dremurr family, they decide it's time to head back to the underground, to help with moving. This ended up saving their life and mental health, yet other problems remain to be doscovered.

Don't Forget [Sans x Female Reader] by GabrielXander

You would think that with how shit your luck is, you would've been dead day one since falling into the Underground filled with scary monsters and a few spooky skeletons. However, much to your surprise, that did not happen (yet). You know how you ended up here, but you don't know... HOW. You're actually in the GAME Undertale now. And to make matters worse, there are some people who KNOW. You're surviving the best you can, but things are only going to get weirder from here on out. Gaster apparently needs your help? You're using the DJ to go to different AU's? You are gay now?- Okay, maybe that last one is just a joke, but still! You can only hope that your instincts are enough to keep you alive in these trenches. On God, they tryin' to drown you in this hoe! {Available on Patreon, Quotev, and Ao3 under GabrielXander}

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Slide 1 of 10

An Oath of Mercy || UnderFell Sans x Reader cover

Bloodfall (An Undertale AU) cover

FlowerPetals (A Flowerfell Fanfic) [DISCONTINUED] cover

Target Settled|Outer!Sans x Killer!Sans cover

UnderVerse: COLLAPSE cover

Protect One Another - US!Papyrus x Reader cover

Your Fault ~ Underfell Fanfiction cover

Discovering My Identity - PaperJam X Fresh (Underhigh fanfiction) cover

Lost Souls- I MOVED THE BOOK SOMEWHERE ELSE, CHECK DESC cover

Don't Forget [Sans x Female Reader] cover

An Oath of Mercy || UnderFell Sans x Reader

One clumsy moment and a broken leg are all it takes to leave you at the mercy of the very edgy and very hostile monsters of the underground. Thanks to your knowledge as a doctor (and oath to do no harm), you're able to convince the Great and Terrible Papyrus to keep you alive. But how are you going to find your way back to the surface with a bum leg and a short skeleton that doesn't seem to like you? | - UnderFell Sans x Human Reader - Enemies to lovers but Fell is the only one hating - Your leg privileges are revoked, and Fell needs to wash his mouth with soap - Flowey is an equippable companion and decides to help you cuz he actually gets something out of it - My own interpretation of UnderFell (tho from what I've seen it doesn't really have a narrative anyway)