Sans, System sans，系统

1. 1 化 As UKB: Seriously, Why Is the Multi-World Prosecutor Still Chasing Me? 化身UKB：不是，多审还在追我 Xiao Yuan-chan小源酱Anime Fanfiction288k WordsOngoing "No System, not invincible, few tearjerkers (because the author isn't very good at writing them either)" AU title: [Undertale: Karma Fire Samsara] (Suitable for casual play, not too exhausting.) Li Yuan stayed up all night grinding CTT, then died suddenly along with his computer. When he woke up, he had become Sans. But the player here didn't seem like a good sort. After twelve consecutive failures, the timeline went a little haywire on the thirteenth attempt. A secret beneath the cliff. A stran 703Reads6.7Score—Shelves

   Reader note

   It's okay. The second book is updated faster and can be updated continuously. The author of the first book is a bit too imaginative and can't fill it in, so the update speed is too fast. Now it's like squeezing out toothpaste, a big lump comes out in a while

2. 2 传 Undertale: Am I Playing Sans? 传说之下：我扮演sans了？ The Sourest Fish with Pickled Cabbage最酸的酸菜鱼Anime Fanfiction775k WordsCompleted (Transmigration + OOC + chat group) Wait, how did I become Sans from Undertale? The System floating in the air answers all his questions. And from the very beginning of his transmigration, he’s thrown into a hell-level challenge. After completing it, he must travel to different parallel worlds under Gaster and the System’s supervision. (Worlds completed so far: Original, Horror, Dust, Swap, KTT, and Insanity) 907Reads7.3Score122Shelves
3. 3 国 National Fate: Sans Can Dominate Even While Frail 国运：sans即使病弱也能横推 TascrilAnime Fanfiction192k WordsOngoing Sans takes part in the National Destiny game. No transmigration plot, but there will be AUs. I’ll do my best to capture Sans’s personality and avoid making him OOC. Sans is the strongest fighter in another world. A fragile mage with infinite magic. No System, no CP, survival game. There will be viewing-room segments where secret identities are exposed. I started writing this because I wanted to write a power fantasy. I changed the cover. I drew it myself. I didn’t have time to change it before b 648Reads8.1Score100Shelves

   Reader note

   There may not necessarily be a system

4. 4 穿 Transmigrated Into Horror 穿越成horror Gray Baiye灰百叶Two Male Leads418k WordsCompleted [System + sans + Undertale derivative] The story of an ordinary transmigrator. Pairing: murder × horror, no fixed roles 920Reads9.2Score113Shelves
5. 5 传 Undertale: TL 传说之下：TL Ah Long Ah Long Ah啊龙啊龙啊Anime Fanfiction47k WordsCompleted TL is an abbreviation for timeline. We don't know where time ends, just as we don't know where it begins. 16Reads—Score—Shelves
6. 6 传 Undertale: Sans in the Apocalypse 传说之下：末世中的Sans ClassicSci-Fi & Apocalypse721k WordsCompleted Told mainly from Sans's perspective. Zombie apocalypse. No overwhelming combat strength [probably]. A System is present. Not a mindless power fantasy, so readers will need to use their heads. Please check the warnings before reading. In the False Pacifist route, led by Frisk, the monsters emerge from the barrier and integrate into human society in almost the best way possible. “Monsters” become a special class of citizens in the country. But happiness is always fragile, and after this strange pl 267Reads8.7Score—Shelves
7. 7 穿 Transmigrating After K-ing My Own Team 穿越自家K后的战斗生活 Taiga and Killing泰迦与killingAnime Fanfiction132k WordsOngoing [Transmigration + no System + no heroine + mindless] An abandoned work… 54Reads—Score—Shelves
8. 8 传 Underfell: From the Start, I Have Sans's Abilities 传说之下开局就有sans的能力 Sao Moshui骚墨水Sports150k WordsOngoing Liu Yang stumbles upon a System and gains Sans’s abilities. He can use them in the real world or transmigrate to various AUs to help or destroy the worlds of other Sanses. What will he do? 229Reads6.8Score—Shelves
9. 9 U Undergoodluck LuckyFlowerAnime Fanfiction148k WordsCompleted [Undertale fanfiction] [Amateur writing (._.)] [No System] [The main cast are all native AU characters] [Any resemblance is purely coincidental] A human child named Clover falls into the Underground. Lucky Clover survives the fall and begins a strange and wonderful adventure through this bizarre place... After exploring the Underground comes a journey through the multiverse. Our AU has no ending!! Main cast: my original character Luck Sans, my OC Clover, and Dust! 73Reads—Score—Shelves
10. 10 传 Undertale! Why Is There a Creeper Here? 传说之下！为啥这里有只苦力怕？ Frosty Someone Is a Creeper霜某是只苦力怕Anime Fanfiction73k WordsCompleted The power levels in this story are completely broken, so please set your brain aside before reading... (Don't worry, they won't fall apart early on, at least not on a narrative level. If you're here for the power scaling, you can let the chapters pile up first.) Perk Helmet arrives in the world of Undertale and sets off on an adventure... With his ability to control things with his mind, he travels through all kinds of AUs, and in the end... 1Reads—Score—Shelves
11. 11 传 From the Start in Undertale, I Create a Sans Chat Group 传说之下开局创建sans聊天群 Lazybones Sans懒骨头杉斯Anime Fanfiction177k WordsOngoing I reincarnated as... Sans. The genocide route?! Liu Feng looks at the human before him as a Gaster Blaster slowly materializes behind him. Today is such a beautiful day... Papyrus, would you like something... How about we team up against the humans? Do I have any other choice? Dust Sans takes Liu Feng’s hand. (I’m new to this, so please be kind!) 351Reads8.1Score102Shelves
12. 12 传 Undertale: The Genocide Route 传说之下【屠杀线】 Kitty Hescu猫猫赫斯克Anime Fanfiction96k WordsCompleted Our battle takes place in the corridor; who wins and who loses is determined by the truth. The killer's heart has already fallen into endless darkness. This is Undertale's [Genocide Route]. 29Reads—Score—Shelves
13. 13 暮 Twilightale 暮光传说twilightale Dream of the Future未来之梦Anime Fanfiction265k WordsCompleted Keywords: Undertale, Undertale, AU, Sans An unconventional Chinese-made AU This story may have no beginning, and may never have an ending. What kind of spectacular tale will unfold on the stage of this multiverse? The blurb doesn't do it justice, so I recommend reading the story itself. This is an unconventional Chinese-made AU. I've left the fandom, and I'm only writing this book to fill in the gaps. I don't want to keep drawing, so I've switched to writing a novel instead. I'm an average writ 261Reads8.6Score—Shelves
14. 14 转 Reborn as Murder 转生murder Lazy Yu懒惰的宇Anime Fanfiction112k WordsCompleted After countless massacres, Murder unexpectedly gained countless memories about UT. He also happened to join a chat group connecting myriad worlds, and began his journey across them. 203Reads6.5Score—Shelves
15. 15 原 Genshin Impact: A Journey Through Teyvat’s Dust 原神：尘埃的提瓦特之旅 Dust Watching the Show看乐子的尘埃Anime Fanfiction101k WordsCompleted [The author only wrote this book out of boredom, so the writing might not be very good.] A white room, A painful memory, A determination that will never die, A madman? A wondrous adventure, A chance to atone, A loyal friend. And so this adventure begins... 115Reads—Score—Shelves
16. 16 原 Genshin Impact: ULBSans Powers from the Start 原神：开局ulbsans能力 Threefold Memories of Days Gone By三重往日时光Anime Fanfiction339k WordsCompleted (There are angst scenes, there are angst scenes, there are angst scenes. Important things must be said three times, though the angst is mild.) Liu Yang was an ordinary high school student on Blue Star. After an accident, he transmigrated to Teyvat and gained a System. From the start, he received the abilities of ULB Sans and became one of the many Archons. Realizing that the Archon War was about to break out, he joined Morax and others in founding the Guili Assembly. But his arrival caused rippl 390Reads7.3Score103Shelves
17. 17 传 Undertale: The Story of an ULB 传说之下：一只ulb的故事 Leader of the Way of Great Peace太平道道主Anime Fanfiction150k WordsCompleted Give him one molecule of oxygen and he'll dance until the world ends. He is the fearsome ulb. General of the Army Douglas MacArthur, speaking from far away on the surface, once said, “If God told me to defeat ulb, then God himself would have to join the battle with a real sword.” Asgore, king of the Underground, also said, “From the moment I appointed ulb as judge, I knew I would never see another slaughterer again.” Frisk, humanity's ambassador for peace, said, “After ulb's trial, I never commi 249Reads7.1Score—Shelves
18. 18 e E4 Enters Aotu World e4来凹凸 User69096785用户69096785Anime Fanfiction944k WordsCompleted After someone dies, God gives him another chance. The protagonist must seize this opportunity. He goes on to become Error 404, an existence that surpasses God. Naturally, his first stop is the Aotu World. 326Reads6.9Score102Shelves
19. 19 原 Genshin Impact: But It’s a Fatal Error 原神：但是致命错误 Crocodile Sauce Sauce Sauce Sauce Sauce沙鳄子酱酱酱酱酱丶Anime Fanfiction58k WordsOngoing [Discontinued] A note before reading: This Fatal Error isn't that Fatal Error. This one is from UT! (Don't mix them up.) Synopsis *Who... am I? *Where... did I come from? *I... think I *for got some thing... *I'm Geno... right? *No, I-I-I am am-I-I-I *fatal_error 4Reads6.5Score—Shelves
20. 20 传 Undertale: A Bad Sans's Journey Through the Multiverse 传说之下：邪骨旅行多元宇宙 oirAnime Fanfiction236k WordsCompleted [Anthropomorphism + multiverse + time-and-space redemption + very little OOC] After escaping the octopus's control, Killer Sans decides to travel across the multiverse, making friends in different worlds and saving other timelines with fates like his own. Along the way, he meets the experienced Murder, the mysterious ulb, and even the eerie, terrifying Sanstrosity. - Killer Sans: That's right, I'm talking to you! Want to be my friend and help me save the universe from disaster? Then type 1! Murd 337Reads8.4Score—Shelves
21. 21 国 National Fate: I Transmigrated as Sans, with Zhongli as My Teammate 国运：穿越sans，队友钟离 Magician of the Rainbow Bridge七彩虹桥的魔术人Anime Fanfiction324k WordsOngoing [Undertale / UT Fan Work] [The national fortunes are not dominated by one country] I know the title's a bit of a mixed bag... But the story itself is even more complicated ( ) [The writing in the first few chapters isn't very polished, so they may not be the best read, but please stick with it for a few more chapters!] A veteran UT player with a complicated background transmigrates, only to find himself caught up in a game of national fortunes? Complete the game across ten worlds, and you can re 725Reads9.4Score110Shelves
22. 22 衫 The Strange Tale of Shan and Yu 衫与鱼的怪谈之旅 Playing in the Mud in a Little Courtyard在泥巴小院玩泥巴Urban100k WordsOngoing [UT + AU + National Fortune + Urban Legends + Not a Power Fantasy + Not Mindless + No System + No Transmigration + No CP + Killer!Sans + Undyne] The author is a lazy slob, so there's no way I'm going to update regularly. This story leans toward comedy, with daily life as its main focus. (Of course, the everyday chapters are the best.) Special notice: You absolutely, absolutely have to read Chapter One! And you absolutely, absolutely have to read the prequel! Second edit: The book has officially 198Reads7.0Score—Shelves
23. 23 传 Undertale: A World Gone Wrong 传说之下，错误的世界 Bored Middle Schooler Jie Rui无聊的初中生劼睿Urban265k WordsCompleted A System that had just passed its evaluation couldn't wait to find its first Host. A Judge who had just experienced an era of peace. Everything seemed to fall perfectly into place, but it was all just part of “his” plan. 49Reads6.5Score—Shelves

    Reader note

    Sans system

24. 24 原 Genshin Impact: Sans's Bizarre Adventure 原神，sans的奇妙冒险 An Ordinary, Anxious Person平凡又焦虑的人Anime Fanfiction532k WordsCompleted [No female lead + not invincible] After countless cycles of peace and slaughter… Sans: Okay, this is really “skull.” I should've known you'd be the variable that showed up in the timeline. G: Countless resets have made this timeline abnormal. You don't belong here anymore. Go out and broaden your horizons. Sans: Okay. (shrugs) I hope wherever I end up has ketchup and hot dogs. (The author is just writing this in their spare time, so there isn't a draft or anything. I write whenever inspirati 422Reads8.4Score105Shelves
25. 25 传 Undertale: She’s Not the Protagonist 传说之下：她不是主角 Cat Cat Dog Dog Cat猫猫狗狗猫Anime Fanfiction369k WordsOngoing [Transmigration] [No Romance] [Ensemble Cast] [Everyone Is Strong] [A Little Golden Finger System, Redemption, and Wild Ideas] [Antagonist] [Slow-Paced and Lighthearted at First, Then a Transitional Middle] [Happy Ending] A lot of UT players transmigrated into this UT multiverse, a place that seemed peaceful on the surface but was actually rife with undercurrents... Narrator: *Among the people working to protect the peace of the universe, there is a hidden killer with the employee number 103. At 91Reads—Score—Shelves

    Reader note

    There are sans, microsystems. Group portrait [get it]

26. 26 我 I Opened a Bone Daycare in the Real World, Shocking the Internet 我在现实开了骨头幼儿园震惊全网 Song of Dreams梦想之歌Modern Romance78k WordsCompleted [This story has CP pairings: Tomato and Wasabi, crnm, ie, and ckc. No male lead. If you don't like it, please don't flame me.][The beginning is an explanatory section for newcomers. If I start introducing test subjects, that means I'm telling you about my original Laboratory series. It's my own creation, so feel free to make derivative works, but don't go too far or ruin the characters.][The first part is an introduction and explanation; the national destiny plot comes later.][One day, the prota 28Reads—Score—Shelves
27. 27 M Murder, the One Who Carries Out the World's Will Murder，践行世界意志之人 oirAnime Fanfiction148k WordsOngoing [Anthropomorphism + System + Native, Not a Transmigrator; Undertale derivative, CP: Murder x Killer] … In the ceaseless cycle of reincarnation, who can remain untouched by endless repetition? Murder, born of Dusttale, was unexpectedly bound to a “System” at the end of a timeline. From then on, he was forced to travel through different times and spaces, helping the native Sans solve problems. After completing eighty-one missions, the plan to erase humanity would finally reach its conclusion! To d 15Reads6.8Score—Shelves

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