#yandere undertale AUs

[yanderes-galore]

Underfell AU Sans romantic concept please?

Sure! I tried to keep him as close to canon as possible while also putting in some of my HCs. He's actually really fun to write :) I hope you like my take... sorry if you don't. There's a gap in the middle due to Tumblr's formatting.

Yandere! Underfell! Sans Concept

Pairing: Romantic/Platonic

Possible Trigger Warnings: Gender-Neutral Darling, Obsession, Violence, Overprotective behavior, Violence, Anxiety, I wanted to make him more possessive (I might in the future but I never thought of it until now), Denial, Kidnapping, Mentioned possible mind break/Murder, Isolation, Stalking, Some jealousy mentioned near the end, Some manipulation, Forced companion/relationship.

I feel Fell! Sans has the possibility of being a terrifying yandere.

He's one of the strongest monsters in the AU and his powers tend to fluctuate due to his emotions.

He's also incredibly stressed all the time from what I've read.

Fell! Sans cares for his brother, they both care for each other actually.

They both want to portray themselves as cool to one another and others.

Fell! Sans is still lazy but also sarcastic.

I know Fell! Papyrus doesn't enjoy killing humans but does it for "sport" to help the guilt, he also does it due to being part of the Royal Guard to protect Sans from Asgore.

However I'm unsure how Sans feels about killing humans according to canon.

I'd assume he'd be indifferent but supports it as it's the law of the land and the job Papyrus is given.

Sans’ obsession was meant to be kept vague however I feel with a human it feels more natural to me?

Maybe you take the role of Frisk or simply aid them.

Either way I'm defaulting Darling to human.

Of course, naturally as the world goes, you end up having to defend yourself against Sans and Papyrus.

Primarily against Papyrus as Sans probably doesn't bother fighting.

Although… you can tell there's some strength there.

Due to what I've read, he radiates power due to his stress.

It's supposedly seen in his jacket at times.

So you have an idea that Sans could easily kill, but are thankful he just chooses not to.

Fell! Sans certainly has an obvious edge in appearance and personality. 

He's very sarcastic with you but in a way you can tell he means well when you befriend him and his brother.

In fact when he forms an attachment he may even show some anxiety about you meeting the other monsters.

You are aware of how easily you could just… die, right?

Even with a flower to guide you, he hopes you can defend yourself and not just talk things out.

Although he is thankful you managed to appeal to his brother enough to spare him.

He definitely tries to act calm in general, especially around you, although there's times he slips.

I imagine Fell! Sans fidgets due to… well… the sheer amount of stress he's under.

Really, who isn't in the Underground?

With Asgore in charge there's strict rules.

Rules that could easily end you as a human.

Sans tries to tell himself to not get attached to you.

He'd be in denial about his obsession.

It's all because he's scared to lose you.

Part of him wants to protect you, yet the other part suggests just letting you go.

The ideas he has tears him apart internally, which Papyrus can definitely tell.

Sans keeps fidgeting and his powers keep fluctuating when he thinks about how he can lose you.

Fanon tends to depict Sans as overly sadistic, while I agree he has aggressive tendencies like everyone in this AU, I don't think he's over the top.

I feel Fell! Sans is more like an anxious and stressed mess more than anything.

Which for him can make him volatile as his powers can be controlled, but are emotion based.

His pent up emotions no doubt drives his obsession.

While Papyrus protects Sans from Asgore, Sans feels like he has to protect you from not only Asgore… but everyone not him or his brother.

While you continue your journey, Sans isn't far behind.

He still has similar powers to his classic counterpart, which means teleportation.

Every area you enter, he's somewhere there.

I never mentioned this in the original draft but I do feel Sans would get possessive/jealous.

It's just not mentioned much in this concept since he's more consumed by anxiety than anything.

But in a way he does feel you two belong together, one way or another.

He would definitely murder, but he has to hold himself back due to his powers.

Which, yes, I assume would mean if he's jealous or enraged enough with you talking to others... his powers may flare.

Papyrus is against this but this human clearly means a lot to Sans.

Admittedly… Papyrus would miss you if you died too.

So he understands where Sans is coming from, it mirrors the care Papyrus has for Sans.

But Sans seems more… intense?

Sans could just feel something akin to close friendship or something more.

Honestly, if a monster nearly killed you, he'd probably snap and use his powers.

Which is why he prefers to just… stick around you everywhere.

Admittedly Sans likes it when you laugh.

He tries not to show it but you mean a lot to him.

The reason he tries to hide it as it shows vulnerability.

But you seem to enjoy his Knock Knock jokes and his company….

You like it because he's more “friendly” than the others.

Honestly, that gives him a bit of pride while also striking vulnerability in him.

Sans really keeps trying to tell himself his obsession is a vulnerability.

He shouldn't be this attached to you.

Yet now he really can't just let you go.

As a result I imagine he'd prevent you from meeting Asgore.

Sure, okay, you may have befriended most of the monsters here…

But not him…

Please not him…

He'll kill you and Sans will snap.

Scared of this he gets more fidgety.

You can probably tell even though he acts collected, he has an aura that scares you.

Sans doesn't know how to explain to you he cares about you.

He just doesn't want to lose you.

So Sans may try to manipulate you into staying with him more to avoid Asgore.

Isn't staying in Snowdin better?

Well… Papyrus may want to see you again!

Y'know… it's futile to go against Asgore, right?

Just… stay with him.

If he has to, he'll use some of his power to lock you away in his home/room.

Look, you don't get it.

Asgore nearly killed Sans before… he could and will do the same to you!

It's behind closed doors that Sans’ facade breaks.

He pulls you closer and mumbles about his fears.

He plans to keep you right here… if you try to leave, he'll know.

At this point he'll kill any monster who tries to hurt you or even goes near you.

Sans curses himself for getting so attached to a human.

However, he's given in now.

He'll keep you away from all the danger.

He'll keep you to himself.

Even if it requires others, including him, to get hurt due to his powers and rage.

[minthy]

The Star Sanses,

with the Map of the soul: 7 song that I think it fits with them, Because I miss 2019.

(forgot to post these doodles here, yay)

Persona: Swap.

"Actually I’m real good but a little uncomfortable,

I'm still not so sure if I'm a dog or a pig or what else,

But then other people come out and put the pearl necklace on me"

(Truth to be told, I have no idea what "swap sans" really is, He's just... well.. A swap, He doesn't even have a personality the silly, He just is there to fit for the plot of your AUs, heheh, Relatable)

Ego: Dream.

"I go back every day, To me of yesterday,

To the life of giving up, I let myself go away,

But in this world, you know, There are truths unchanged,

Time rushes ever forward, There's no ifs, buts, or maybes"

(I don't think he can get over what happened, his heart is big and his ego is bigger than to let him ask for guidance and support, man release us)

Shadow: Ink.

"I wondered everyday how far I'd go,

I came to my senses and I find myself here,

Yeah, hmm, shadow at my feet,

Look down, it's gotten even bigger"

(No matter how great high and mighty he's getting, the more the shadows of his past and constant need for stimulation are driving him to a point of despair and unsatisfaction, get a grip)

[hheisa]

Some News about this guy!!!

By a request from a friend, I'm going to start calling "Yandere Blueberry" as "BloodBerry" !!!!

This is because the expression "Yandere" is considered stereotypical for people with BPD and I also like the name BloodBerry

Hhehehhehehe BloodBerry

Also, to clear something: I'm not trying to romanticize this kind of stuff 💀 my only objective when drawing BloodBerry is to make him look creepy :p

[darkpetal16]

Play as a CUSTOMIZABLE scientist who catches the deranged attention of a siren while visiting an Arctic research base. 

Game includes:

Play as a smart scientist who makes really dumb decisions. 

Play as a smart scientist who makes excellent decisions that lead to self-preservation. 

Get adopted by a misanthropist socially awkward Dadster

Be stalked wooed by a delusional siren

Be kidnapped

Drive a snowjet! 

Race a friendly companion.  

Binge watch a series without realizing how much time has passed you by. 

Be drowned

Enjoy your stay at a five-star arctic research base that has zero casualties so far. 

Why do you keep finding bodies—

This is a 15+ romance/horror with an obsessive love interest. Please read the complete warnings list inside the game if sensitive or easily triggered. 

This game has one complete route to a "good" ending, and 9 "bad" endings with plans to add additional routes / bonuses. Siren!Sans belongs to @llamagoddessofficial on tumblr/ao3. AU was used with permission, although adjusted for funsies. (:

[greepuffer]

Three Sans, one you. This story has an open ending...I guess ;}

[confettibonez]

I wanna boil him

[zu-is-here]

Red

Fluffynightkiller Week by @help-im-a-gay-fish

An Unhealthy Obsession AU by help-im-a-gay-fish

Ccino by black-nyanko

Nightmare by jokublog

Killer by rahafwabas / rahaf-wabas / rahofy-sketch

[cakesmelons]

Yanberry, although a yandere, is still Blue

y'all can imagine whoever you want as the person Blue's obsessed over <3

[pepperonipizzafan1]

sory ikeep postinghim

[lavenderskye29]

The boys from @llamagoddessofficial ‘s Coraline au!

[artale07]

aww cuddly Sans is soo cute =)

Ko-fi

[yanderes-galore]

Screenshot this as I am not comfortable tagging OP! A bit OOC for my Fell! Sans but I'll do what I can! Here's a short argument scene (I was not given a plot again....)

Prompts Here

Yandere! UnderFell! Sans Prompts 2, 9, 12

"If you want me to beg, then I’ll beg for you."

"I will never let you leave me."

"I’m only this desperate for you."

Pairing: Romantic/Platonic

Possible Trigger Warnings: Gender-Neutral Darling, Obsession, Overprotective behavior, Isolation, Swearing, Kidnapping implied, Forced companionship.

"What? Do you want me to grovel at your feet just to make sure you don't get yourself killed out there?" The skeleton hisses at you in an irritated tone. "I will never let you leave me."

"I can handle myself out there, you don't need to be around me all the time!" You hiss back, narrowing your eyes. The door out of Sans' room has been locked your entire argument. You just know he's using his powers to keep it that way.

"You don't fucking get it!" Sans scolds, keeping his ground. "You can't live out there without me. You'll die... why don't you see that!?"

"I'm going to be fine. You need to let me out." You reason, but Sans refuses to listen.

"Don't act like you're such a damn expert!" Sans spits. "If you want me to beg, then I’ll beg for you! You. Will. Die. End of story!"

You can tell by the flare of his coat that you're making him frustrated. You're wary of his mood and back down a bit. Sans notices and takes a deep breath.

"I’m only this desperate for you..." Sans sighs, looking weary. "Does that mean anything to you? Can't you tell I care about you? If you go out there... they'll kill you. They'll take you away.

You feel sympathetic towards the skeleton in front of you. You want to reach out but you're afraid.

Especially when you see the glint in his sockets.

"Which means I'm willing to do anything to keep you here with me..." Sans laughs, stepping closer. You feel bones at your back. A chill climbs up your spine like spiders.

"Including hurt you..." Sans whispers, placing a gloved hand on your cheek.

"So are you sure you want to press me anymore than you have?"

[help-im-a-gay-fish]

Fluffynightkiller week 2024:

Day 3 Blind.

hehehe someone is in troubleeeeee. I Got reminded of zu's work from last yearrrrrr. Some dark romance is goooodd.

Original killer belongs to rahafwabas

Original ccino belongs to black-nyanko

Original nightmare by jokublog

[hheisa]

He love you! :)

[teasworldstuff]

AU Sans as ASMR!!

i spent ages on this (longest drawing yet!!) and i rlly hope it does well despite being such a niche concept 😭😭

Ink: Sketching You (comyet)

Dream: Positive Affirmations (jokublog)

Horror: Eating/Chewing (sour-apple-studios)

Error: Spiderweb/Strings (CrayonQueen)

Nightmare: Slime (jokublog)

Underswap! Sans: Personal Attentjon (popcornpr1nce)

Murder: Scratching (ask-dusttale)

Killer: Whispers (rahafwabas) [tumblr doesn’t like the other word]

Cross: Fluffy Mic (jakei95)

[confettibonez]

Get a helmet damn