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Sick To Death (Of Me Chasing You) by CrossoverAU
Fandoms: Undertale (Video Game), Alice by Heart - Sheik/Sater/Sater & Nelson
06 Jul 2025
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Summary
Raine was sick. Really sick.
The kind of sick where, despite not knowing what she had, she knew she didn't have long left.
Her best friend Sans knew that too.
Not wanting her to live her last moments trapped in her house, Sans read her one of her favorite stories, Alice in Wonderland.
While chasing her through the pages, Sans learns that he loves her too much to let her die.
Will he be able to let her go or will he try to selfishly stop the clock?
Aka an Undertale/Alice By Heart crossover fic because I couldn't find one
Note: knowledge of Alice By Heart isn't needed to read this fic!
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After almost eighty-nine genocidal routes and forty-six pacifist routes.
Frisk, wanting to mature a little and wanting to save the monsters after playing so much with the resets, decided to start a new pacifist route. At the beginning everything went as it should and there was nothing strange, but...
Why does Papyrus sometimes look at him with terror?! Why do they all have scars on their bodies?! Where are the human souls and where did they go?!
Frisk was very confused and didn't know what to do, he tried to do a reset, and in the new route... nothing changed and everyone still had scars.
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Parental Union by DemonicPrince23
Fandoms: The Owl House (Cartoon), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia (Anime & Manga), Murder Drones (Web Series), Phineas and Ferb, Undertale (Video Game), Deltarune (Video Game), Five Nights at Freddy's, Harry Potter - J. K. Rowling, Bendy and the Ink Machine, Star Wars - All Media Types, Undertale Yellow (Video Game), & More - Fandom
06 Jul 2025
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To my sister, assuming she finds this: PLEASE DON'T KILL ME! I saw the ship listed in the list of ships and was intrigued. I'm sorry.
To anyone confused: She and I know what I'm talking about. If she doesn't... Well, I'll survive for sure, unless I do something dumb and show her it. If she does... Well, I'll need to pray.
Credit for the idea goes to a Discord friend of mine, Voltage, who isn't a fanfic writer, but came up with the idea.
Credit for each individual fandom goes to their creators. I am none of them.
Credit for the story itself, however, is mine.
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Summary
Chara died, and wake up again as a ghost, the first thing they see is a monster trying to kill a human kid, so they make the most reasonable assumption they can think of: The human did something so evil even nice monsters want to kill them. (they're wrong) They will do something about it even if they can't interact with the world, other than talking to the human, they just need a good enough plan... they just have to be creative!
Frisk just fell in a hole and now there are people trying to kill them and also they're haunted... which sounds worse than it is, because they are haunted by this... small kid, who probably can just talk to them and nothing else, the one problem is that they keep telling them to go fight someone for some reason, and they are being very annoying about it...
...Anyway basically Chara is a small gremlin child that gives Frisk headache occasionally... sometimes... usually... they'll be freinds eventually. (didn't take that long, honestly)
(This used to be a one shot, you can read the first chapter that way if you want to, the story kind of change... a... more than a bit, so I changed the summary, the old one for the Oneshot is in the first Chapter Note below here)
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The Doctor's Descent by Feanyx1
Fandoms: Undertale (Video Game), Doctor Who (2005), Doctor Who, Deltarune (Video Game)
04 Jul 2025
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Summary
He thought that the radiation would kill him. He thought that his time as the Doctor would come to sad and brutal end. He was wrong. And that was so much worse.
In his efforts to find himself, and without his companions, he accidentally stumbles onto a monstrous civilization miles below the Earth. With his newfound DETERMINATION and some new allies, he'll come to realize what it truly means to be a friend, and learn how to live his last lives with his head held high.
And make sure that, just this once, everybody lives.
OR
Undertale but the Tenth Doctor replaces Frisk. Fluff, angst, AUs, and timeline shenanigans ensue.
*No knowledge of Undertale or Doctor Who is required, though it is helpful if you've experienced at least one of them.
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Unexpected Hero by LemonCake64
Fandoms: Undertale (Video Game), The Legend of Zelda & Related Fandoms, The Legend of Zelda: Twilight Princess
04 Jul 2025
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Summary
“Not so fun being stuck in some loop right? Trying to fight to protect what ya got, not getting a choice in it. If I had the choice I wouldn't remember either.” The words oddly felt comforting. Link let out a slow breath, closing his eyes for a brief moment.
He didn't feel alone for the first time in a long time.
And that?
That was terrifying.
“To be honest, I kinda gave up a while ago. Just sat back and let the chaos go on, felt like nothing I did mattered anymore. Everything would just be reset anyways. Stopped caring what happened, that was until you showed up.” The skeleton’s eyes bore back into the Hylian.
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This is the final part to the Kingdomtale pacifist series. I have a few other works I wanna post as well that are also kingdomtale related so keep an eye out for those. Also if you haven’t read parts 1 or 2, go read them! They’re gonna help explain how we got to this point in time.
Warning: may contain mentions of abuse, violence, death, dust, blood, depression, attempted suicide, cursing, romance, weird/Toby logic and ships. If any of these bother you then why are you still here? Otherwise, if you are fine with these things please enjoy reading this grand finale! This takes place after part 1, humanity’s creed, and part 2 of this series. Our protagonist Frisk is only referred to as a girl or she/her when it’s the humans talking due to the time setting and because of the morals discussed in humanity’s creed. Otherwise they are referred to as they/them (nonbinary pronouns. Or whatever other nicknames I mentioned in parts 1 and part 2). All oc’s are owned by me, other characters are owned by Toby Fox.
- Language:
- English
- Words:
- 12,050
- Chapters:
- 15/16
- Hits:
- 42
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Summary
Horrortale Sans X Reader
Undertale Sans X Reader
Last you knew you were looking into his eyes as he watched your attempt to kill yourself. Of course, your attempt was futile, seeing as though you couldn't die. You expected it to go on forever until you stopped, but, you definitely didn't expect to be staring into those same eyes, only they weren't the same. He wasn't the same. What happened? Why are you here? What kind of sick joke was this? You weren't supposed to be here, and someone was going to make sure you left.
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This is a Horrortale x reader but for a while, as you will see it'll be also an undertale x reader. There is some sexual tension sometimes but no smut since reader is genderless.UPDATING SCHEDULE IS INCONSISTENT
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Tyrant Xilian enters the Undertale Universe by XeptorKingGG
Fandoms: Undertale (Video Game), Original Work
02 Jul 2025
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Tyrant Xilian's avatar had arrived in what looked to be an alternative reality from his own. This reality was what looked to be from the famous game Undertale, known for it's complexity and wide establishment of fan creations. He took the appearance of a monster called "Monster Kid", tricking others with his disguise he played along, mimicing the monster perfectly.
However, the current games route he was in was known as the genocide route.- Language:
- English
- Words:
- 9,119
- Chapters:
- 12/?
- Hits:
- 52
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Summary
Concept: UTY AU from the perspective of a military veteran investigating the disappearances of the eight human children last sighted near or at the base of Mt. Ebott.
After having completed her eight years of service, she goes home to find her younger sibling has disappeared. As she inevitably finds and descends the entrance to the underground, PTSD surfaces. This soldier has seen the worst of humanity, and battles the sins of her past actions.
Clover has made a sacrifice, but things end up differently than what his friends expected. Having found an amnesiac Fox monster, the Ketsukane family takes him in as their own.
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Elephant in the Room by liverposy
Fandoms: Undertale (Video Game), Deltarune (Video Game)
30 Jun 2025
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Summary
...And there's a skeleton you've never met before on your couch.
Sans mistakes your apartment for the one him and Papyrus just moved into. He worked a late night and didn't even notice!
The skeleton brothers happen to be your neighbors, and wackiness (and more!) ensues.there will be angst and cool other stuff like...!
thank you for reading my summary :3 -
Undertale: Hearts and Souls by UnknownOrigin0410
Fandoms: Undertale (Video Game), Undertale Yellow, Undertale: Red and Yellow, Kingdom Hearts (Video Games), Disney - All Media Types, pixar movies - Fandom, Dreamworks movies
30 Jun 2025
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It has been over a year since Frisk freed the monsters from the Underground. Throughout said year Frisk has had to act as the ambassador for all of monster-kind, doing their best to ensure that monsters were getting the rights they deserved in order to properly be integrated with life on the surface. Things were going great, and a picnic with the friends that Frisk had made throughout their journey was in order to celebrate everything they have managed to accomplish so far. That is, until Heartless begin to invade the world and drag it into darkness, separating Frisk and Chara from the others as they find themselves in a strange world and obtaining the ability to wield a weapon known as the keyblade. While reluctant to fight against this dark threat, Frisk and Chara must traverse worlds with the help of others who have been facing the darkness for a long time, all in the hopes of finding their friends and family as well as bringing back their world from the clutches of darkness.
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Follow Grillby as he ventures through the underground after a genocidal child emptied it.
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If you're going through hell, keep going. [FILE 314] by Bad_Dreems
Fandoms: Undertale (Video Game)
29 Jun 2025
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Summary
Well the world is gonna end
So dance around the fire that we once believed in
Wanna tear it down again, now
Cause there's nothing left for us to be
Give it up the sons of anarchy
So come around and have another round of me.-The Offspring
Series
- Part 5 of Dreamer's End
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Frisk couldn't recall exactly how many times he had been in this same position.
He had lost count on how many times he tried and failed. Lost count on how many times he had died. How many times he had RESET.
It didn't matter what he did, he always ended up failing. No matter what choice he made, he failed.
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.[GAME OVER]
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.CONTINUE [RESTART] ?
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.* you called out HER name……
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.* .......and SHE answered.
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- Part 1 of UnderVanquish
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Ralsei had memorized The Prophecy top to bottom, front to back. There will be three heroes, which will appear to stop The Roaring, saving both Light and Dark Worlds. Of this, they were absolutely certain.
But...something about The Prophecy always felt off.For one, it never specified that the fated Prince of Dark — who was most assuredly Ralsei themselves — was an android. A replica, of someone that never existed in this reality.
Secondly, it got the name of the second hero, The Monster, incorrect. The Girl wasn't Susie — it was Sue. And their hair wasn't a wild, flowing mane, either.
The broad strokes all follow The Prophecy, but as they journey on more adventures, it becomes clear that the tiniest details are wrong, wrong, wrong. Can they really trust it, then? Is there really only one way to save the worlds?
A novelization of DELTARUNE, following alternative versions of each character in the main cast. While the story mostly goes the same, the changes in the characters mean changes in the smallest of details, casting doubt that The Prophecy is correct in the first place.
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She fell chasing her sister. Now, disguised as a monster, she’s gambling everything to get Frisk out alive—including trusting a lazy skeleton who sees through her lies. With Asgore’s knights closing in and the king needing one last human soul, survival demands shortcuts through glowing caves and MTT Resort glitter. But Sans’s bone-dry wit and hidden power blur the line between using him… and losing her heart underground.
Neutral Route | Slowburn Sans/Reader | Found Family | Protective Siblings | 2016 Undertale fic vibes
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FRISK GETS THE FLU SND NOW EVERYONE IS WORRIED
(LET ME KNOW UR THOUGHTS AND IF I SHOULD CONTINUE TO UPDATE THIS)
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Life On the Surface by RetroWrites
Fandoms: Undertale (Video Game), Deltarune (Video Game)
24 Jun 2025
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Frisk has freed the monsters.
Now all they need to do is to live on the surface.
Campy story with plot and sad stuff on top of regular Undertale shenanigans.