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  1. 19

    Life in the Underground by

    Fandoms: Deltarune (Video Game), Undertale (Video Game)  

    28 Nov 2025

    Tags
    Summary

    After decades of being separated, Spamton had made it into the Underground and reunited with his husband. With their future regained, all that was left to do was catch up on lost time and enjoy the rest of their lives together. It wouldn't always be easy, but it'll be worth it.

    This is where all the one-shot ideas I have for this AU are going to be posted!

    Series
    Language:
    English
    Words:
    14,524
    Chapters:
    2/2
    Comments:
    67
    Kudos:
    263
    Bookmarks:
    19
    Hits:
    1,649

  2. 3

    The Forsaken and the Cherished by for thovcs

    Fandoms: Forsaken (Roblox), Undertale (Video Game), but not a crossover kinda situation  

    07 Sep 2025

    Tags
    Summary

    Seven was confused.

    Seven was really confused.

    As the Destroyer of Creation, he had a very important job to do every day; keep the balance of the Multiverse, and make sure there were never too many AUs being made. He used to love the job, as it fulfilled his sadistic pleasures - but even now, despite those same looks of fear, he saw it more as a chore than a way to vent out his frustration and violent urges. After a couple centuries of doing the same thing, anyone could get tired of it. He never allowed himself to feel bad, though. Emotions were bad for the job.

    But, because he was the Destroyer of Creation, Seven always looked out for AUs to destroy. Sometimes he came across empty AUs, but he never paid any attention to them because there were never any residents.

    This time, there was.

    OR

    When the Destroyer of Creation - Seven - discovers across a lost child in a blank AU, he’s forced to take him in and raise him as his own. Sometimes, he feels as if this is how things were always meant to go.

    Only problem is.. he lacks any code.

    P.S; This is not a traditional crossover fic, this is a fic where 007n7 is in the role of Error Sans, and Chance is in the role of Ink Sans.

    Series
    Language:
    English
    Words:
    3,319
    Chapters:
    1/?
    Comments:
    32
    Kudos:
    7
    Bookmarks:
    3
    Hits:
    77

  3. 2

    Longfics by

    Fandom: but not a crossover kinda situation, Forsaken (Roblox), Undertale (Video Game)

    18 Nov 2025

    Words:
    46,235
    Works:
    3
    Bookmarks:
    2

  4. *

    Trustfall by

    Fandoms: Undertale (Video Game), Deltarune (Video Game)  

    27 Sep 2025

    Tags
    Summary

    Ever since the Monsters were sealed away to the Underground after the war, Spamton had tried his hardest to live his life without his monster husband by his side. But memories weighed heavy on him, unable to let go of the past and the future they were supposed to have together.

    So, for the small chance of seeing him again, Spamton leaves it all behind and makes the jump.

    Series
    Language:
    English
    Words:
    11,968
    Chapters:
    2/2
    Comments:
    138
    Kudos:
    1,075
    Bookmarks:
    178
    Hits:
    7,919

  5. 9

    Trustfall AU by

    Fandom: Deltarune (Video Game), Undertale (Video Game)

    28 Nov 2025

    Words:
    26,492
    Works:
    2
    Bookmarks:
    9

  6. *

    Milfzun but like. Gamer Goat Edition by for Pseudo_Nym

    Fandoms: 人渣反派自救系统 - 墨香铜臭 | The Scum Villain's Self-Saving System - Mòxiāng Tóngxiù  

    23 Jul 2021

    Tags
    Summary

    Binghe falls down the abyss. What happens next is a pivotal time, where our protagonist can go down one of two roads: genocide route, or milfzun pacifist route

    In which an Undertale AU kinda works surprisingly well for Bingqiu, actually

    Language:
    English
    Words:
    2,205
    Chapters:
    1/1
    Comments:
    45
    Kudos:
    875
    Bookmarks:
    160
    Hits:
    4,326

  7. 1

    Promising Young Women by

    Fandoms: Dangan Ronpa Series, Persona 5, Persona Series, Undertale (Video Game)  

    12 Nov 2025

    Tags
    Summary

    “You know…” she spoke. “Covering up a murder is not what I had in mind when I said we should go on a double date.”

    [Junkan Month Day Twelve: Double Date.]

    Series
    Language:
    English
    Words:
    2,235
    Chapters:
    1/1
    Kudos:
    2
    Bookmarks:
    1
    Hits:
    53

  8. 1

    Junkan Month 2025 by

    Fandom: Dangan Ronpa Series, Deltarune (Video Game), Kagerou Project, Parties are For Losers - Ferry (Songs), Persona 5, Persona Series, Undertale (Video Game)

    30 Nov 2025

    Words:
    20,271
    Works:
    30
    Bookmarks:
    1

  9. 2

    the true lab. by

    Fandoms: Dangan Ronpa Series, Undertale (Video Game)  

    22 Aug 2025

    Tags
    Summary

    “There used to be two boys I hung out with,” Nagito tells her. “They were twins. Hajime and Izuru. I didn’t know their circumstances, but we knew each other.”

    The snow is cold, in snowdin. Chiaki shivers into her kitten hoodie, watching Nagito as he watches the distance. “I think you would have liked them.”

    “What happened to them?” Chiaki asks him.

    He turns to her, smiling, “They fell down. It’s— a natural illness of monsters, sometimes. A state close to death, what you humans call a ‘coma’. They were taken by the royal scientist and her assistant. They were as good as dead anyway, so it didn’t seem like a problem that they would be used in research to break the barrier.”

    Chiaki shudders, “So they… They’re dead?”

    “See, that’s the thing,” Nagito says. “We never got their dust back.”

    [KomaHinaNami Week 2025 Day Six: Fantasy AU/Other AU.]

    Series
    Language:
    English
    Words:
    653
    Chapters:
    1/1
    Comments:
    2
    Kudos:
    21
    Bookmarks:
    2
    Hits:
    298

  10. 15

    ~ SkeletonBound ~ by

    Fandoms: Undertale (Video Game), Mother 2: Gyiyg no Gyakushuu | EarthBound  

    18 Mar 2023

    Tags
    Summary

    It has been 4 months since the Barrier was broken and Monsters have been free to the Surface. Asgore Dreemur - King of the Monsters - managed to make peace with the humans and allowed them to stay on the surface without conflict. The Humans have helped the monsters settle on the Surface, even making a small town full of monsters near MT.Ebott…

    The Monster population isn’t big - compared to the human population in the city - but there are still various species of Monsters, from Snowdrakes to Elementals, all having their own characteristics and traits. But the among all of the Monster population, the two ‘Skeleton Brothers’ certainly stood out the most. No one knows where they came from or their origin, one could say they just appeared out of thin air and just settled into Snowdin…

    Who are these Skeleton Brothers? Where did they come from? These answers only start to appear after reaching the surface…

    Series
    Language:
    English
    Words:
    14,457
    Chapters:
    14/20
    Comments:
    53
    Kudos:
    109
    Bookmarks:
    15
    Hits:
    2,086

  11. 3

    crossover works by

    Fandom: Assassination Classroom, Code Geass, Dangan Ronpa - All Media Types, Dangan Ronpa 3: The End of 希望ヶ峰学園 | The End of Kibougamine Gakuen | End of Hope's Peak High School, Dangan Ronpa Another Episode: Ultra Despair Girls, Dangan Ronpa Series, Dangan Ronpa Zero, Dangan Ronpa: Trigger Happy Havoc, Danny Phantom, DCU, DCU (Comics), Deltarune (Video Game), Fruits Basket, Gravity Falls, Hunger Games Trilogy - Suzanne Collins, Kagerou Project, Knives Out (Movies), Mahou Shoujo Madoka Magika | Puella Magi Madoka Magica, Mekakucity Actors, MILGRAM (Music Videos), Miraculous Ladybug, My Little Pony Generation 4: Friendship Is Magic (Cartoon 2010), Mystic Messenger (Video Game), New Dangan Ronpa V3: Everyone's New Semester of Killing, Ouran High School Host Club - All Media Types, Over the Garden Wall (Cartoon & Comics), Parties are For Losers - Ferry (Songs), Persona 5, Persona Series, Puss in Boots (DreamWorks Movies), Re:ゼロから始める異世界生活 | Re:Zero Starting Life in Another World (Anime), Steven Universe (Cartoon), Super Dangan Ronpa 2, Super Dangan Ronpa 2.5, Tangled (2010), The Owl House (Cartoon), Undertale (Video Game), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… - 山口悟 | My Next Life as a Villainess - Yamaguchi Satoru (Light Novels), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Anime), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Manga), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Visual Novel), 人渣反派自救系统 - 墨香铜臭 | The Scum Villain's Self-Saving System - Mòxiāng Tóngxiù, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia (Anime & Manga), 天官赐福 - 墨香铜臭 | Tiān Guān Cì Fú - Mòxiāng Tóngxiù, 天官赐福 | Heaven Official's Blessing (Cartoon), 推しの子 | Oshi no Ko (Anime), 推しの子 | Oshi no Ko (Manga), 文豪ストレイドッグス | Bungou Stray Dogs, 琴浦さん | Kotoura-san, 魔入りました! 入間くん | Mairimashita! Iruma-kun | Welcome to Demon School! Iruma-kun (Anime), 魔入りました! 入間くん | Mairimashita! Iruma-kun | Welcome to Demon School! Iruma-kun (Manga), 魔道祖师 - 墨香铜臭 | Módào Zǔshī - Mòxiāng Tóngxiù

    07 Nov 2025

    Words:
    346,299
    Works:
    141
    Bookmarks:
    3

  12. 4

    puppet by

    Fandoms: Undertale (Video Game), MILGRAM (Music Videos)  

    23 Sep 2024

    Tags
    Summary

    Frisk finds themselves in Milgram. But how do you judge someone for crimes that never technically happened?

    Series
    Language:
    English
    Words:
    1,869
    Chapters:
    1/?
    Comments:
    5
    Kudos:
    20
    Bookmarks:
    4
    Hits:
    201

  13. 5

    We All Have Tales by

    Fandoms: Deltarune (Video Game), Undertale (Video Game)  

    23 Sep 2025

    Tags
    Summary

    Just their luck to break their fall on top of those pretty yellow flowers get a 'minor' concussion and be taken in by a tall goat monster and her barely tolerable skeleton roommate. It could be worse, if the mean purple lizard monster and the anxious deer ever decide to quit trying to kidnap them.

    Deltarune/Undertale AU - What if Kris fell into the underground years after an abandoned neutral route, where a fishy empress is out for human blood for killing their best friend.

    Language:
    English
    Words:
    6,543
    Chapters:
    3/?
    Comments:
    11
    Kudos:
    38
    Bookmarks:
    5
    Hits:
    669

  14. 29

    Shen Yuan’s Underground Adventure by

    Fandoms: 人渣反派自救系统 - 墨香铜臭 | The Scum Villain's Self-Saving System - Mòxiāng Tóngxiù  

    14 Aug 2025

    Tags
    Summary

    “Well?” The ghost snapped. Shen Yuan jumped at the harsh tone, before hissing at the pain that brought. The ghost rolled his eyes, pointing at the jar. “That’s to heal you! Get on with it!”

    Even with the yelling, Shen Yuan didn’t move for a long, long moment after that. He simply stared at the ghost, taking in his fancy looking robes, his angry face, the way that he was completely see-through.

    And then, with all his heart, Shen Yuan said softly, “What the fuck.”

    —————

    Or, Shen Yuan did not mean to fall into a world of drama-looking people, but now he has to find a way out if he ever wanted to go home again. If only the people he met along the way would stop trying to kill him!

    An Undertale SVSSS fusion, but no knowledge of Undertale needed.

    Language:
    English
    Words:
    32,660
    Chapters:
    10/?
    Comments:
    15
    Kudos:
    90
    Bookmarks:
    29
    Hits:
    2,324

  15. 17

    SIkuna's Guide to Undertale by Anonymous

    Fandoms: Undertale (Video Game), 呪術廻戦 | Jujutsu Kaisen (Manga), 呪術廻戦 | Jujutsu Kaisen (Anime), Canon? We Don’t Know Her (Discord Server)  

    15 May 2025

    Tags
    Summary

    It takes a few blinks for his eyes to adjust.

     

    The slightly-sweet smell of pollen, the warm softness beneath his palms and brushing his cheeks, filters through his awareness as his eyes flutter open. He squints against the dim amber light that pours in from a hole in the cavern ceiling far up above him and, for a while, he dazedly watches dust motes shimmer and dance as they’re caught in the rays.

     

    It’s quiet. Vast and cavernous, pale stone walls decorated with lichen and the odd bit of moss, harsh edges softened and smoothed over by the trickling rivulets of golden spilling sun. Nikita pushes himself upwards, head pounding as his limbs tremble, and ah.

     

    Welp. He fell.

    AKA. The fic where 15+ authors shove their Sukuna self-inserts from Jujutsu Kaisen into Undertale. For funsies!

    Language:
    English
    Words:
    2,161
    Chapters:
    1/?
    Collections:
    3
    Comments:
    16
    Kudos:
    47
    Bookmarks:
    17
    Hits:
    1,261

  16. 4

    A Hateful Heart leads to Complete Chaos by

    Fandoms: Undertale (Video Game), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga)  

    30 Sep 2023

    Tags
    Summary

    Everyone has at least one of the seven soul traits (even if they don’t know it):
    Kindness—Green
    Patience—Light Blue
    Integrity—Blue
    Bravery—Orange
    Justice—Yellow
    Perseverance—Purple
    Determination—Red

    Shinobu has researched Soul Traits for 4 years now. So when certain people find out their Soul Traits she has the answers.

    When she fights against her sister’s killer, she uses her Soul magic but finds out her sister’s past mistakes may cause… complications…

    Language:
    English
    Words:
    201
    Chapters:
    1/?
    Comments:
    2
    Kudos:
    30
    Bookmarks:
    4
    Hits:
    465

  17. 3

    author's favorites (my favorite works I've done) by

    Fandom: Assassination Classroom, Avatar: The Last Airbender, Corpse Party (Video Game), Dangan Ronpa - All Media Types, Dangan Ronpa 3: The End of 希望ヶ峰学園 | The End of Kibougamine Gakuen | End of Hope's Peak High School, Dangan Ronpa Another Episode: Ultra Despair Girls, Dangan Ronpa Series, Dangan Ronpa Zero, Dangan Ronpa: Another Episode, Dangan Ronpa: Trigger Happy Havoc, Danny Phantom, Doki Doki Literature Club! (Visual Novel), Gravity Falls, Hunger Games Trilogy - Suzanne Collins, Kagerou Project, LISA (Video Games), Mad Father (Video Game), Mahou Shoujo Madoka Magika | Puella Magi Madoka Magica, Marvel Cinematic Universe, Mekakucity Actors, MILGRAM (Music Videos), Miraculous Ladybug, My Little Pony, My Little Pony Generation 4: Equestria Girls (Cartoon 2013), My Little Pony Generation 4: Friendship Is Magic (Cartoon 2010), Mystic Messenger (Video Game), New Dangan Ronpa V3: Everyone's New Semester of Killing, Paper Mario Series (Video Games), Persona 5, Persona Series, Re:ゼロから始める異世界生活 | Re:Zero Starting Life in Another World (Anime), RWBY, Steven Universe (Cartoon), Super Dangan Ronpa 2, Super Dangan Ronpa 2.5, Super Mario & Related Fandoms, Tangled (2010), The Owl House (Cartoon), The Witcher (TV), Thor (Movies), Undertale (Video Game), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… - 山口悟 | My Next Life as a Villainess - Yamaguchi Satoru (Light Novels), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Anime), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Manga), 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… | My Next Life as a Villainess (Visual Novel), 人渣反派自救系统 - 墨香铜臭 | The Scum Villain's Self-Saving System - Mòxiāng Tóngxiù, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia (Anime & Manga), 天官赐福 - 墨香铜臭 | Tiān Guān Cì Fú - Mòxiāng Tóngxiù, 天官赐福 | Heaven Official's Blessing (Cartoon), 天官赐福 | Heaven Official's Blessing (Webcomic), 文豪ストレイドッグス | Bungou Stray Dogs, 琴浦さん | Kotoura-san, 陈情令 | The Untamed (TV), 魔道祖师 - 墨香铜臭 | Módào Zǔshī - Mòxiāng Tóngxiù

    07 Nov 2025

    Summary

    A place for what I feel like are my best works. 267 works may seem like a lot, but that's out of 715 works, so that's only 37% of my overall works if my math is right. Includes all fandoms.

    Words:
    845,136
    Works:
    326
    Bookmarks:
    3

  18. 6

    My DR3 rewrites by

    Fandom: Dangan Ronpa - All Media Types, Dangan Ronpa 3: The End of 希望ヶ峰学園 | The End of Kibougamine Gakuen | End of Hope's Peak High School, Dangan Ronpa Another Episode: Ultra Despair Girls, Dangan Ronpa Series, Dangan Ronpa Zero, Dangan Ronpa: Trigger Happy Havoc, Gravity Falls, Mahou Shoujo Madoka Magika | Puella Magi Madoka Magica, My Little Pony Generation 4: Friendship Is Magic (Cartoon 2010), Mystic Messenger (Video Game), New Dangan Ronpa V3: Everyone's New Semester of Killing, Steven Universe (Cartoon), Super Dangan Ronpa 2, Super Dangan Ronpa 2.5, Undertale (Video Game), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia, 天官赐福 - 墨香铜臭 | Tiān Guān Cì Fú - Mòxiāng Tóngxiù, 天官赐福 | Heaven Official's Blessing (Cartoon), 文豪ストレイドッグス | Bungou Stray Dogs

    07 Nov 2025

    Summary

    Does not include any non despair ones, I don't think. Even if they're only non despair due to Junko's untimely death. Unless that non despair is time travel, in which case they are included.

    Words:
    370,226
    Works:
    130
    Bookmarks:
    6

  19. 32

    Once Upon A Dream by for Shell_or_seashore

    Fandoms: Voltron: Legendary Defender  

    10 Jan 2023

    Tags
    Summary

    Keith lives a pretty standard life.

    He's got a boring office job, coworkers with conventional names, and a monotonous 9 to 5 work week. He's beyond hoping that anything interesting will happen to him. That just isn't the way the world works.

    At least, it isn't the way his world works. A chance diversion to his routine leads Keith down a path he is destined to follow, one that leads him to impossible truths and enduring love.

    Language:
    English
    Words:
    6,425
    Chapters:
    1/1
    Comments:
    14
    Kudos:
    219
    Bookmarks:
    32
    Hits:
    1,364

  20. 2

    the second & third human. by

    Fandoms: Mahou Shoujo Madoka Magika | Puella Magi Madoka Magica, Undertale (Video Game)  

    25 Jul 2025

    Tags
    Summary

    *A pair of beautiful dolls. Keep together. Do not separate.

    Series
    Language:
    English
    Words:
    240
    Chapters:
    1/?
    Comments:
    6
    Kudos:
    8
    Bookmarks:
    2
    Hits:
    175

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