Most plots hinge on the contrast between his cheerful act and a darker reality. Common conflicts involve him hiding an injury or a secret from his brother, dealing with the emotional fallout of a reset he didn't cause, or trying to prevent a timeline collapse while maintaining his 'nothing's wrong!' facade. His relationship with a now-lazy Papyrus is central; protecting him often forces Sans to confront his own limits. Crossovers with other AUs usually explore how his swapped personality clashes with the expectations of other characters, creating instant friction.
This is a really niche corner of the Undertale fandom, but the core of most Underswap Sans fiction tends to revolve around identity swaps of the skeleton brothers themselves. You've got Sans, who now has Papyrus's energetic, justice-loving persona, but he's still saddled with the immense power and sometimes the latent guilt of his original timeline. A lot of plots mine conflict from that dissonance—this Sans tries to be upbeat and heroic, but the weight of his 'original' memories or his magic being fundamentally different creates a constant internal struggle. I've read a few where he grapples with feeling like a fraud because he's acting a part, or where his attempts to be 'the cool one' spectacularly backfire because he can't shake his more detached, analytical nature.
External conflicts often mirror that. Since Papyrus is the lazy, pun-loving one in this AU, you get a dynamic where Sans is desperately trying to keep everything together and protect a brother who might be more cunning or secretly powerful than he lets on. It flips the caretaker role on its head. You'll also see a lot of fics exploring his relationship with an Underswap Alphys, where he might be her overenthusiastic royal guard counterpart instead of a laid-back friend, which creates a whole new kind of lab-based tension. The tropes aren't wildly different from other AUs, but the flavor is distinct because it's about performance versus essence.
Honestly? It feels like half the fics I stumble into are just rehashes of the Geno plotline but with the names swapped. Sans has a bad time, resets go wrong, he remembers everything and it breaks the cheerful facade. It's a bit repetitive. The more interesting ones to me are the slice-of-life attempts that ask what Sans would actually do with Papyrus's life. Like, how does this Sans run the sentry stations? Does he make overly complex puzzles with convoluted rules, or does he get bored halfway through and just put up a 'Beware of Dog' sign? I saw one fic where his conflict was purely bureaucratic—trying to file perfect reports for the Royal Guard and driving Undyne nuts with his attention to detail. That felt fresher.
Another common thread is the 'swap within a swap'—characters from the original timeline or a different AU showing up and being completely confused by this version of him. That mismatch is a reliable source of both comedy and drama, depending on how the writer plays it. It's less about epic multiverse battles and more about personal recognition, or the lack thereof.
2026-07-20 14:06:30
18
Tingnan ang Lahat ng Sagot
I-scan ang code upang i-download ang App
Kaugnay na Mga Aklat
Reborn as the villain's obsession [MM romance]
Bluebutterflywrites
10
5.6K
Adrian died with fury in his heart, hating the tragic ending of his favorite novel.
The villain deserved better.
But the story was never written for happy endings.
Betrayed by everyone he trusted, feared by the entire world, and ultimately destroyed by the plot itself—Cassian Nyx, the infamous Demon Lord, was never meant to be saved.
Until Adrian woke up inside the story.
He didn't reincarnate as a harmless bystander. He woke up as Prince Elian Ashford—the tyrannical prince destined to destroy Cassian.
Worse, a cold, ruthless World System instantly locks onto his soul, forcing him to keep the original tragedy on its "correct" path.
[MISSION: MAINTAIN STORY STABILITY]
Failure Penalty: Immediate Death.
Trapped between a lethal penalty and his own morals, Adrian chooses a dangerous path: pretend to follow the plot while secretly rewriting the villain's destiny.
But there’s only one problem.
The more Adrian tries to save the villain, the more the dangerous, obsessive Demon Lord begins to love him.
Cassian Nyx is a monster feared by the entire kingdom. He trusts no one. Until Adrian. For the first time in centuries, the scarred Demon Lord begins to hope for a future where someone finally stays.
Now, the original hero has arrived, and the System is forcing the final execution. Every choice Adrian makes pushes the world further into chaotic plot deviation.
Adrian must make his final choice. Will he obey the System to save his own life? Or will he destroy the entire story itself just to save his villain?
Genre: BL Fantasy Romance / Transmigration
Tropes: Obsessive Demon Lord ML × Reincarnated Prince MC, Saving the Obsessive Demon Lord / Destroying the Plot for You, System Missions, Enemies to Lovers, Slow Burn, Angst with Comfort, Soul Bond.
Steamy Fairytales Collection: An 18+ Dark Fairytales Series
Joy Apens
10
100.9K
A retelling of several of the most famous fairy tales with a kinky, dirty twist. Each story is about 30,000 words so sit back, grab some holy water and relax! It's time to sink in 10 deliciously dark and twisted fairytales! Highly erotic and brimming with dark desires, don't say I didn't warn ya!
18+ Dark Fairytale Series
Rumpled (Retelling of Rumplestiltskin)
Sinderella (Retelling of Cinderella)
Allissa in Wankerland (Retelling of Alice In Wonderland)
Friends With Sexy Benefits (Retelling of Hansel and Gretel)
Snow White and the Seven Hunks (Retelling of Snow White and the Seven Dwarfs)
Red (Retelling of Little Red Riding Hood)
Tangled (Retelling of Rapunzel)
Bella and the Beast (Beauty and The Beast)
Maid For Pleasure (The Ugly Duckling)
Goldilocks and the 3 Were-bears (Goldilocks)
WHAT DO YOU DO WHEN YOUR HUSBAND AND HIS BEST FRIEND ACCIDENTALLY SWAP SOULS AND TO SWAP THEM BACK YOU HAVE TO BE MARKED BY BOTH OF THEM AT THE SAME TIME OR JUST PICK ONE?
Do you go to the man with your husband's face, his familiar hands, his familiar voice — knowing it's his best friend's soul looking back at you through his eyes?
Or do you go to the man with his best friend's body, every tattoo, every scar, every inch of him you were never supposed to want — knowing your husband's heart is beating inside that chest?
Maya Sinclair has exactly forty days to figure it out before the curse makes the swap permanent.
The problem is she's been in love with both of them for longer than she's willing to admit. And the bigger problem? They're starting to figure that out.
Two men. Two bodies. One woman.
She has thirty days to break the curse.
And she has two men in the wrong bodies, with every reason to hate each other — who are both, somehow, choosing her and even choosing each other.
Some curses aren't punishments.
Some curses are the only way the universe could think to tell you the truth. And that one choice could change three lives.
What choice would Maya make?
THIS BOOK CONTAINS EXPLICIT SEX SCENES,POSSESSIVE ENERGY, AND INTENSE EMOTIONAL TENSION AND BETRAYAL, READER’S DISCRETION IS ADVISED. SPICY CHAPTERS WOULD BE INDICATED WITH THIS SYMBOL ~~~. ENJOY!!
"I, Alpha Harden, accept Caitlin Graham as my Luna. She is my true mate." When those words echoed, Elara turned numb. She suffered a double betrayal from her friend and devoted boyfriend, and her sick father was framed and thrown in prison. Still, she chooses not to succumb to the pressure of becoming the Alpha's mistress. Elara finally accepts his rejection and is sent out of the pack as a rogue without a wolf.
To save herself and her father, Elara turns to Arthur, the Alpha of the Dawn pack and Harden finds her with him.
When they meet again, Arthur teases Elara in front of Harden, "Do you still want me to make love to you, tonight?" Arthur asked, and she replied much to Harden's surprise, "Arthur, can we do it tomorrow night?"
Seeing her curl up in another man's arms, a lone tears slip from his eyes.
Harden felt nothing but regret for losing the only woman he ever loved. He wanted her to come back to him, he wanted to tell her how much he regretted his actions, and he was ready to give up everything, including his position as Alpha of the pack. Will Elara go back to him? Read to find out.
Luca Graven, an orphan cursed by poverty, worked under the man loathed the most— Dante Solis. He was a wealthy, powerful mafia leader who had the strongest men, including Luca himself cowering in fear.
Unfortunately, Dante took a liking to him. He brought him into his home, enslaved him, treated him like rubbish….but, he never hurt him beyond his limits. Maybe that was why Luca never fully hated him, and maybe, just maybe, that was why he wanted him.
Until, a new version of him shows up. He looked exactly like Dante, same voice even, but completely different personalities. This version listened, cared for him, no longer saw him as a mere slave, he nurtured him and treated him like he meant something for once. Of course to Luca, Dante had miraculously grown a heart but that person that showed him kindness and mercy wasn’t Dante. It was Allen Pierce—his doppelganger.
Now torn between two different people, yet drawn to each of them and their different souls, he has to make a decision.
But they don’t make it easy. Luca wasn’t the only one fighting to choose, they were both fighting to be chosen.
“Farewell to you who never deserved the love I gave. I want you to suffer as I did, to feel the pain as if they were your own; every agonizing second of it.” I smirk as my throat stings, coughing up more blood. Tears streamed down his bloodshot eyes, a satisfaction I never expected I’d feel at my dying moments.
“N-no! I’m sorry, please . . . please don’t leave me!” he held me close to his trembling chest, his sobs reverberating through the air — the last I breathed in before I gave in to death’s arms.
Or so I thought.
In a world of power and love, Morana Everette, the Luna of the Dark Moon Pack, basks in a life of perfection until fate intervenes. Her husband's true fated woman emerges, shattering her idyllic existence and casting her aside. In a final act of sacrifice and a dying curse, she finds herself swapping bodies with her husband, and with his emotions still intact, she is forced to experience the attraction towards the girl who ruined her life. While Logan experiences the agony she once endured in her past. As deities continue to play with their destinies, emotions run high, loyalties are tested, and the cruel game of switch unfolds. Can they break free from this cycle of misery, or will they forever be bound by fate's twisted design?
***
The novel is Written by Dinni Dee and By Miss Joye's Outline.
The novel is copyrighted by Ideaink Six Cats.
Lately I've noticed a distinct pattern emerging, which feels less about random imagination and more like the fandom collectively processing something. There's this heavy focus on 'what if Sans had a normal life'—coffee shop AUs, roommate scenarios, domestic fluff with the human. It reads like a communal sigh of relief after the intensity of the Underground. We watched him carry the weight of timelines and resets, so giving him a break feels necessary. The other major strand revolves around prequels, exploring his relationship with Gaster or the other skeleton brothers before things fell apart. That's where the angst lives.
Then there's the complete tonal shift into hurt/comfort, which often blends with the first two. Someone finds him collapsed after a nightmare about resets, or Papyrus has to patch him up after a secret fight. It's a specific flavor of vulnerability we never fully saw in-game. Sometimes it veers into outright whump, which isn't really my thing, but I get the appeal—taking a character who's always three steps ahead and seeing him genuinely, physically helpless creates a different kind of tension.
What surprises me is how rare pure crack-fic is. You'd think with his puns and fourth-wall breaking, it'd be everywhere, but most writers seem to treat him with a sort of melancholic reverence. Even the funny stuff is tinged with existential dread. Maybe that's the core theme everyone's circling: the tragedy of a funny guy who knows too much.