What Are The Best Chara X Papyrus Fanfiction Story Ideas?

I'm partial to cross-universe ideas that throw them into a totally new context. Like, a 'Freaky Friday' body swap after a magical accident. Papyrus wakes up in Chara's body, feeling the echo of LV and the weird weight of a human form, and his immediate reaction isn't panic but a deep concern about how to properly care for these 'fragile human bones.' Chara, stuck as Papyrus, is initially furious but then weirdly empowered by his physical strength and the simple, direct way monsters perceive the world.

The humor of Papyrus trying to explain his newfound 'determination' to a bewildered Sans while baking a cake 'with the power of friendship!' is gold. But the real meat is Chara experiencing, for the first time, what it's like to be perceived as inherently good. Everyone in Snowdin greets them warmly, trusts them instantly. It's a kind of psychological torture that's the exact opposite of what they're used to. Do they lean into the role, finding a strange comfort in the performance? Or do they sabotage it, desperate to prove that goodness is just a costume anyone can wear? The swap wouldn't last forever, but the aftermath—both of them carrying a faint understanding of the other's existence—could be haunting.

AUs are the obvious playground. In a reversed 'Underfell' or 'Horrortale' setting where Papyrus is the ruthless one and Chara is just a lost, terrified human, their dynamic completely inverts. Papyrus might see Chara not as a threat, but as a curious, breakable toy. His 'friendship' becomes a possessive, obsessive game. Chara's survival depends on playing along with his twisted version of 'bonding,' which could involve anything from deadly puzzles to being forced to listen to his monologues.

It strips away the expected niceness and asks: what would Papyrus be like if his core traits—persistence, theatricality, a desire for companionship—were filtered through malice instead of joy? And how would Chara, stripped of their usual power, react? Would they try to manipulate him, find a crack in his armor, or would they, in a dark mirror of the usual dynamic, start to see a kind of warped sense in his madness? The story becomes a tense, claustrophobic power struggle in a grim castle, far from Snowdin's cozy lights.

Chara and Papyrus is such a weirdly wholesome dynamic if you think about it? Like, one's the embodiment of chaotic violence and the other is the purest skeleton who just wants a friend. A concept I keep coming back to is them getting stuck together somehow after a reset glitch—Papyrus remembering just enough to be confused, Chara being their usual creepy self but weirdly disarmed by his relentless, unconditional friendliness.

Maybe it starts as a kind of psychological horror where Chara is just playing along, waiting for the perfect moment to shatter Papyrus's worldview, but the sheer, stubborn force of his niceness starts to... work? The real drama wouldn't be about redemption exactly, but about Chara facing something their determination can't overcome: a kindness that refuses to break. The setting practically writes itself—forced proximity in Snowdin, Papyrus trying to teach them puzzle etiquette, Chara begrudgingly finding Sans's terrible jokes less irritating when filtered through his brother's earnest laughter.

You could even flip it: a timeline where Papyrus, through some anomaly, is the only one who can perceive Chara's ghostly presence post-pacifist run. He'd just assume they're a new invisible friend who needs cheering up, narrating his entire day to them, trying to knit them a sweater. Chara, who expects fear or anger, is instead met with a baffling, one-sided friendship they can't escape. The horror becomes a different flavor—not of being hunted, but of being truly seen and accepted by the one soul you feel least deserving of it.

Honestly, most takes I see either soften Chara way too much or make Papyrus secretly dark. I'd rather read something that leans into their fundamental mismatch. Imagine Papyrus deciding, for no reason anyone can fathom, to 'adopt' the strangely intense human child. He drags them on utterly mundane errands—grocery shopping for spaghetti ingredients, visiting the library for puzzle books. Chara's internal monologue is full of contempt and violent fantasies, but their actions are increasingly passive, just... following along.

The comedy writes itself from Papyrus's POV: he's finally found a friend even more in need of guidance than Sans! The tragedy writes itself from Chara's: they're the fallen human, the demon that comes when you call its name, and they're currently being lectured on the proper way to stir noodle water. The story's tension wouldn't come from external threat, but from waiting for the other shoe to drop. Does Chara snap? Do they get bored and leave? Or does Papyrus's bizarre, persistent light actually start to thaw something frozen solid ages ago? It's a slow, weird character study built on non-sequiturs and awkward silences.