Ello readers! This is pretty much my first crossover and I've noticed there aren't a lot of Undertale and Attack on Titan crossovers in the internet and a majority of them are actually crack-fics. So I thought of writing one with a few more serious elements in it to compensate for the lack of fanfictions.

One of the main reasons why I decided to start one is because I love these two fandoms to DEATH. I'm actually an avid reader of the AoT manga, so this work will obviously follow its storyline. There is also going to an eventual Levi x oc in this, but I'll mainly focus on the story rather than the romance (but I will promise you a few spicy bits here and there 3)

I'm going to alter a few plotlines in the AoT universe, but I'm pretty excited to let the characters interact with each other. Another thing is that I'm making the skeleton brothers more humanoid here. Their race is going to be called 'Calx' which is the root word of calcium. Their still going to have a few of their monster attributes, like a black sclera with a white iris and their hands made of hardened skin and bone.

This is also going to follow the Handplates AU and a lot of its elements. This is actually in a setting where there have been a continuous number of genocide routes. The true pacifist ending has not been attempted yet. And please, PLEASE bear with my horrible grammar and be kind enough to point out any errors committed.

|Murals, dust and bandannas|

The paint fumes filled her nostrils with its addictive scent. Arial shut her eyes, eyeing the stormily painted wall beside her as she lay pathetically among the empty cans of spray-paint and stencils. The heavy feeling was weighing down on her chest again and she found herself curling up into a fetal position, pulling her winter jacket and striped green bandanna closer to her small body.

She heard Sans and Papyrus below her in the kitchen. The taller male's loud and boisterous voice resonated through the walls and the shorter one's silent baritone had a mild lilt to it. Arial turned on her back and looked at the ceiling, blowing a messy black bang out of her good eye. The white pupil against the black sclera flitted about slightly. Then she got to her feet.

"What's the use." She muttered morosely. "What's the fucking use?"

If she could name one of her acute phobias, other than her fear of the dark, closed spaces and needles, she could say that she was terrified of sleeping. Every night, she's been having the same nightmare. A human in a striped shirt, a red knife, Papyrus' red scarf lying in his dust, meeting the brother killer in the CORE entrance, one of her murals behind her, fighting them, dusting.

Darkness.

Can't move.

Can't breathe.

A deathly familiar voice; some sort of garbled speech and a pair of white hands dragging her deeper.

Then she wakes up.

Sometimes the dreams had variations, where Sans takes Papyrus' place in Snowdin and he's the one who dies. Sometimes, Sans takes Arial's place in the CORE and she finds herself confronting the demon in the last corridor, alone and terrified, the only thing in between them and Asgore.

She was careful not to let her brother's know about the nightmares, but they were catching on. Papyrus wasn't an idiot and Sans was nowhere close to one. They could see the bags under her eyes every morning and they would get darker and darker as the nightmares grew worse.

Opening her bedroom door, she glanced down the staircase to see her older brother collapsed on the sofa, fast asleep. Papyrus was still in the kitchen, preparing more inedible spaghetti. After breakfast, the three of them were going to leave for sentry duty, like any other day.

She skulked down the stairs and unceremoniously plopped on Sans. He barely cracked an eyelid, his long white hair tied up in that messy bun, mussing up a little at the impact. Arial shut her eyes, pursing her lips.

"I want a hug, Sans." She mumbled. The white haired male raised an eyebrow, flashing her his own white iris. He held up his hand, pushing her forward back playfully.

"What's the occasion? I thought you set up a camp in that room." He asked with his tired yet calm smile, but he still pulled her closer and cuddled her gently. Arial hummed, shutting her eyes. Her edginess disappeared and she found herself calming down.

"Nothing. Hugs are nice." She replied. "I feel safe in a hug. Hugs are forever and you cannot deny me of that right." She hugged Sans even tighter at that point, tire wearing her down quickly. The older brother sniggered, lifting himself up.

"You seem oddly poetic. Tibia honest, your constant patellin on cuddles tickles a real funny bone." He joked. "Do you have any clue how cheesy that is?"

"Now you've made me mozzerable." She hit back. There was a loud clatter which clashed with Sans' deep laughter. Papyrus stuck his head out, eyes wide with annoyance. Arial coughed and discreetly pointed to Sans, averting her eyes.

"SAN WHY MUST YOU BE SUCH A BAD INFLUENCE ON SISTER ARI?!" Papyrus screeched with exasperation. She glanced down at his tomato stained apron with amusement, the frilly pink fabric now dyed red like it was straight out a horror movie. She could barely make out its personalized script (block letters with kiss the cook sprawled across. Here, cook was crossed out and 'THE GREAT PAPYRUS' replaced it) through all the tomato puree and…she blinked. Was that-

"Hey, Paps, not to impose or anything, but uhh…is that coal dust?" Sans pointed out, voicing out her thoughts. Papyrus looked at his apron then back at the shorter skeleton with a raised eyebrow as if he couldn't see the bigger picture.

"WELL, OBVIOUSLY!" HE EXCLAIMED. "UNFORTUNATELY, THE GREAT PAPYRUS MAY HAVE FORGOTTEN TO BUY PEPPER IN MY TRIP TO THE STORE. WE ALL KNOW HOW BLAND MY DELIGHTFUL SPAGETTI IS WITHOUT IT." Arial nodded slightly, a smile quirking her lips. "SO, I USED MY MAGNIFICENT (AND SMART) HEAD TO FIND A SUBSTITUTE!"

Arial blinked, nodding slightly faster while stroking her chin.

"Right, good call." She agreed, not having the heart to tell her brother that one, his spaghetti's taste was indescribable and two, coal dust was certainly NOT a substitute for pepper. "Why coal though. And where did you get it from?" she added. Sans sat up, to her disappointment and she tugged harder, refusing to let go.

"Noooo Sans, I wasn't done hugging!" she protested. Sans chuckled, ruffling her hair affectionately.

"WELL," Papyrus began, tapping his chin. "COAL DUST IS BLACK, LIKE PEPPER, SO IT WOULD BE THE PERFECT ALTERNATIVE. DON'T YOU AGREE?"

"Yeah, Papy, totally." Arial grinned.

"In fact," Sans started, a playful lilt in his tone. "We could say the spaghetti will be carbon pretty nicely." Papyrus jaw dropped and he let out an exasperated "NYEH!" at the (need I say horrible) pun. He turned to Arial, who sat back with a goofy smile on her face and placed his hands on his hips.

"Sister, I Pray You Not To Encourage His Terrible Habit." He begged. She shrugged, leaning back and pulling her knees closer to her body.

"Don't sweat it, Papy." She assured. "All my ideas for puns argon." Sans snorted, his smile growing wider, if it were possible. Papyrus wailed, waving his arms in the air. He wasn't really upset, she knew Papyrus all her life for the love of the angel, and that slight smile that twitched on her older brother's face was proof enough. He finally calmed down and returned to the kitchen. Arial flopped back, shutting her eyes lethargically, sleep suddenly hitting her like a ton of bricks before she could scramble out of its way. She was sinking into the darkness, unable to move an inch.

The song played in the background. Arial found herself in a gold corridor, breathing in and out heavily. The sun was shining through the stained glass windows and if it weren't for her current situation, she would have relaxed and admired the scenery. But her muscles were tense and her magic was keening around her, the piano solo of a faintly familiar theme playing in the background.

She knew where she was. The judgment hall, or the last corridor. Asgore had shown her and her brothers this place when they were still young and vulnerable. It brought back quite a few memories, some of them not very happy.

A soft glow emitted in front of her and her head snapped towards the source. She took a deep breath in, fear clouding her senses and she instinctively pulled Sans' blue hoodie and Papyrus' red scarf closer for comfort. She had run all the way from Snowdin to get here and there was no way she was going to let that…thing get past her.

She will fight. For Sans and Papyrus.

Footsteps echoed through the hall and she saw the silhouette of a human, around ten to eleven years old gripping a dusty knife in their hand. Their hair was shadowed out by their brown locks. She froze at the sight of them, then pursed her lips, eye light of her right eye disappearing into the inky darkness of her sclera.

"Tell me, kid, did you enjoy killing everyone I loved?" she asked. "Because it sure as hell feels like it." They suddenly smiled, taking a step forward, holding their blade up. Arial nearly took a step back, but she stood her ground.

"I don't really know what your reasons are for killing us. We never really did anything wrong to you so kid, please, let's try talking this out." She continued. "Papyrus always told me to look for the best in everyone. I want to believe you can change, so drop the knife."

They didn't listen to her pleas and Arial found herself sighing, shoving her hands in the pockets of the dusty hoodie. Her winter jacket and bandanna were a tangled mess at her waist where she tied them up to make room for Sans and Papyrus' clothes. Shutting her eyes, she finally looked up.

"It's another day today, lonely, terrifying yet cruelly beautiful. With every sin you've committed by killing my race," she stated, holding up her gloved right hand. A green flame burst out of her eyes and the human's SOUL was pulled out, turning from a deep red to a shimmering emerald. " h."

Her theme started playing in the background as she sent the first wave of bones at them.

"ARIAL!"

She woke up in Papyrus' arms, her eye glowing a deep shade of green. Arial sucked in a breath, tears welling in her eyes as she struggled to get out. Papyrus held her down however, his physical strength exceeding her lamentable excuse for muscle. Her eyes widened, suddenly finding it hard to breath. She let out panicked cries, gritting her teeth.

"Ari, hey, hey it's okay." Sans murmured, kneeling next to her and running his hands through her hair. "Just breathe, okay? Breath."

There was a faint hum in the air as his and Papyrus' eyes lit up their respective shades, a light blue and a gentle orange. Arial followed Sans' advise, inhaling and exhaling slowly. The pulsing in her SOUL slowed down and her deep emerald eye's glow dimmed to a softer shade. Papyrus kept his arms around her, hugging her gently.

"Are You Alright?" he asked quietly. She nodded and he let her go. Arial winced when a jolt of pain shot through her head and she rubbed it, groaning softly. "What happened?" she asked. Sans' eyes turned darker at this, the blue flame that lit.

"YOU WERE HAVING ANOTHER NIGHTMARE, SISTER." Papyrus replied instead. "IT WAS PRETTY BAD; YOU SUMMONED ONE OF YOUR BLASTERS AND DESTROYED A PART OF THE HOUSE."

Arial's eyes widened and her head whipped to the side. Papyrus' comment was pretty blunt and the wall across her had a huge hole with singed wood bordering it. She did that?! Oh god, why did she have to abolish the walls of her house because of a stupid nightmare?

"Listen, kid, you don't have to come with us for sentry duty today." Sans said. Papyrus nodded in agreement.

"TRUE, I WORRY ABOUT YOU NOT GETTING ADEQUATE REST." He added. "AS MUCH AS I HATE ANY OF YOU BEING LAZY, EVEN I, THE GREAT PAPYRUS KNOW THAT SLEEP IS HIGHLY NECESSARY FOR OUR BODY."

Panic grew at her throat and she shook her head.

"No, please, guys, I'd rather be anything but alone." She begged. "I'm not even that tired."

Sans blinked a couple of times, then shrugged, his usual lazy smile spreading across his features. "Fine." He muttered. "But don't work yourself to the bone, sis. You've been getting femur and femur nights to sleep."

Arial felt a weak smile spread across her face as Papyrus inhaled sharply and stiffly walked out of the door. The oldest brother chuckled, helping her up and shoving his hands into his hoodie pocket.

"Heh, in all the excitement, Paps forgot about his spaghetti." He mused. "How about we hop over at Grillby's for a burger?"

"Sure, but just as long as Bobtail doesn't try groping me again." She stated drolly, pulling her fur-lined hood up over her head.

Arial froze at the sight of a human standing next to Sans. Their clothes and hands were dusty and she could make out the hilt of a knife in their pocket. Panic shot through her again and she had half an urge to scream at Sans to get out of the way while Gaster Blasting the demon's ass to the afterlife. However the look in his eyes stopped her and she stood there stiffly, listening to her brother speak to them casually, like it didn't just kill a bunch of monsters.

She was almost convinced it wasn't a human with all that dust that coated it's stench.

"Well, you might wanna hide. My brother Papyrus is coming this way." Sans counseled. "Behind that conveniently shaped lamp or…uh never mind" The human however, stood their ground, unsettling stare on Arial before taking a step towards her. Arial hissed, fear shaking her very SOUL, but she narrowed her eyes at them.

"Get away from me." She snapped, taking a few steps back. The gritting of familiar footsteps met her ears and Papyrus appeared from the trees, scarf waving in the wind behind him. For a split second, Arial saw his dust on the snowy floor and she shuddered, forcing the disturbing image out of her head.

"SANS, ARIAL, HAVE YOU FOUND THE HUMAN YET?" the taller monster asked, head high. He stopped at the sight of the human, blinking. Arial blinked with him.

"Yeah." she and Sans said simultaneously, enthusiasm devoid from their voices. Papyrus grinned triumphantly.

"WOWIE, GUESS THAT'S SETTLED THEN!" He declared, turning around smartly and sprinting behind the trees again, probably to get his puzzles ready for the human. Arial gulped and looked back at them, eyes wide. "Wassup, other than the rocky ceiling, that is…" She tried to joke, but trailed off when they stared at her in an unsettling way. "Hey, are you just gonna stare at me or…?"

The human hummed and tramped through the snow, only to be stopped by Sans whose smile was unsettlingly tense and forced. They paused, glancing back ever so slightly, the disturbing glint in their eyes shining a little brighter.

"Well, I'll be straightforward with you." he stated with mild boredom, like he's been through the same song and dance before. "My brother would really like to see a human so…" His eyes zeroed down on them dangerously, almost as if he wanted to erase them from existence. "Y'know, it'd really help me out if you know…you kept pretending to be one."

Arial stood aghast for a few seconds before she saw Sans beckon towards her. She jogged up to him, mind buzzing with disbelief at what she just witnessed as they walked in the opposite direction. There was silence between them and she looked back to see what that thing was up to.

The human stared after them for a moment then continued up the path and Arial turned to Sans with shock. "We're just going to let them through?!" she exclaimed. "That thing could hurt Papy, Sans! I'm not as good at reading people like you are, but…I know that…THING killed innocents."

Sans sighed, a fatigued look flashing through his white pupils. He looked just as tired as Arial did at that moment and almost seemed like he wanted to tell he something that weighed down on him. Arial knew him longer than anyone had (with Papyrus as an exception) and she saw his tense posture.

"It's not much use, really Ari." Sans stated, his deep voice suddenly devoid of emotion. "It'll happen again. The kid will get to you and Paps and…" he broke off and she felt suspicion pang at her SOUL. How was Sans so sure about that? Why was Sans so sure about that? She tried to search his face for answers, but as usual…she got none.

"I don't get what you're trying to say." She mumbled, pausing for a second before a smile spread across her features. "D, do, do do, dooo

I love you, like a temmie in a cube

Like the RUINS rubble heap and

New home's crowded street.

I'd love you, through Snowdin and Waterfall,

And lava's steady crackle

Now, crap I'm talking in my sleep

Abouuuut YOU!"

Sans let out a loud snigger when she shot him the jazz hands, her off-beat voice resonating through the air (unfortunately, singing wasn't Arial's forte, but she used to play the acoustic guitar for Napstablook every now and then). The little poem the three siblings had made up when they were kids was always a way to lift her oldest brother' feelings when he was down.

She leaned against him lazily and Sans casually draped his arm around her, slightly cheered up. Arial felt herself slip into the void along with Sans, the cold wind picking up powdery white snow and pine needles gently. She blinked a couple of times.

Something about that human was familiar…

"SANS, ARIAL WHEN'S THE HUMAN SHOWING UP?" Papyrus asked, hands on his hips while he eyed the path that disappeared in the direction of Sans' sentry station. Arial hung back, terror gripping at her SOUL. She glanced at the side, lips pursed. "I WANT TO LOOK MY SUNDAY BEST…OR AT LEAST MY THURSDAY PRETTY GOOD."

"Don't you only have one outfit?" Sans reminded, a smile pulling at the corners of his mouth. Papyrus blinked, tapping his chin, then shrugging.

"YEAH, BUT I COULD STYLE MY HAIR." He decided optimistically. Arial sneaked a look at his ash-blonde locks, not really having the heart to tell him that his hair wasn't going to…NOT stick out. She reminisced on the old memories they had, when Papyrus had bought a limited edition MTT hair gel to tame his mop. That didn't work, after dumping the entire bottle onto his hair, they just sprang back to its original state.

Sans seemed to be thinking it too, a weary smile on his face. "Oh. Right. Good idea." He chuckled, glancing down the path. "Say, why don't you look over there?"

Arial felt her eyes narrow at the figure that appeared through the mist, knife gripped in their hands. They walked forward a couple of steps and Papyrus turned to Sans. Sans turned to Arial and Arial turned to Papyrus, before long they began to spin at a dizzying speed. She stopped twirling, stumbling forward a little and gasping for breath. She was pulled into a huddle before she could recover and Papyrus was bouncing in place with energy.

"SANS OH MY GOD! I'M DIZZY. WHAT AM I LOOKING AT?" He giggled childishly, teetering to the side a little. Somehow, the oldest brother had recovered his brief pirouette and steadied him and Arial, stopping them from falling face-first into snow. She managed to find her balance and steady her spinning head.

Her eyes landed on the human and she tensed up again, watching them roll their eyes with disgust. They glanced at her, a terrifying flash in their eyes, and she wanted to turn around and run in the other direction, screaming. Sans looked at her, raising his eyebrows slightly. She got the hint, sighing internally. Well, she'll do this for Papyrus. Sans and Arial gestured dramatically at the human.

"Behold!" he declared. Papyrus, looked in the direction of her outstretched hand, excitement bubbling in his face. "OH MY GOD!" He did a double take, scanning the snowy stretch. He then turned to his two shorter companions, unimpressed and a little exasperated. "WHY ARE YOU TELLING ME TO LOOK AT A ROCK?"

Arial's eyes widened and she snorted. "Papy, what's in front of the rock." She prodded. Papyrus looked at the dust covered human, confusion passing over his face. His white iris dimmed a little with shock. "OH MY GOD, I HAVE NO IDEA WHAT THAT IS!" He protested, waving his arms at them. She nodded slightly, knowing how it took her a few moments to register that they were from the surface.

"Well, it's not a rock." Sans played along, helpfully (note the sarcasm.). Arial wanted to facepalm when he refused to come right out and tell him that it was a human. Trust her brother to be cryptic as a joke.

"And it's not a Calx either." She added, just to make things a little easier. There was messily hidden unease and vindictiveness in her tone. Papyrus stopped, excitement returning in barrelful's at the comment.

"NOT A ROCK OR A CALX?" He mused. "OH NO! WITH THE PROCESS OF ELIMINATION, I CAN ONLY ASSUME THAT IT'S A HUMAN!" he clapped his hands, his ADHD addled body bouncing and prancing in spot. Arial pulled her striped bandanna closer, eyes narrowing at the thing who watched the whole thing with no emotion whatsoever on their face.

Spot on. She thought drily, shoving her hands into her winter coat, the white fur of the fleece lined jacket tickled her cheek gently as the wind picked up again. Papyrus cleared his throat, puffing hs chest out for dramatic tension.

"HUMAN, PREPARE YOURSELF!" He declared enthusiastically. "FOR HIGH JINKS, LOW JINKS, DANGERS PUZZLES, CAPERS, JAPERS, BEING CAPTURED AND OTHER SORTS FUN ACTIVITIES." Arial snorted again, papyrus turning back to shoot her a small glare. Sans simply grinned lazily, hands in his hoodie pockets.

"Because a game of capture the human is always fun." He deliberated, shooting Arial a wink. Arial waggled her eyebrows.

"And of course, the provision of comic relief by…" she paused. "The punning Calx duo!" she decided to pose dramatically for effect, performing a well-articulated dab, arms outstretched in Sans' direction. His grin widened as he replied to his signature shrug, a drumroll sounding in the background.

"NYEH!" Papyrus yelled with frustration, throwing his arms into the air. He pulled his demeanor together, however when he realized he still had an audience. "REFRESHMENTS WILL BE PROVIDED…IF YOU DARE!" he turned around sprinting into the next sector, probably to spruce up the electric maze he was working on. Arial jogged a little ways after him, then paused, glancing back to see Sans glaring at the human with slumped shoulders, disappointment was stretched across his face.

"And you don't even bat an eyelash." He stated blandly, turning to her. Arial stayed there for a few minutes then sent him a brisk nod, sprinting after Papyrus as fast as her short legs could go.

"Papyrus, we need to go back home." Arial begged, fear and despair cracking her voice. They were walking towards the outskirts of Snowdin, Sans staying behind to show the human their final puzzle. Arial frowned bitterly at the thought. Puzzle after puzzle, the human walked over her brother's enthusiasm. He used to stare at them with growing nervousness and confusion every time they walked forward mid-explanation. She could sense their intentions. She knew that thing was going to make a move and try killing her brother.

She just hoped Sans could handle them alone.

"You've SEEN the dust all over them, Papy." She continued. "That human is bad news, even SANS says so. We need to get to a safer place." Papyrus stopped abruptly, snow ceasing to crunch under his red boots. He glanced at Arial for a moment, a conflicted look on his face. He rested his hands on her shoulder, the white hard matter that strongly resembled that of a skeleton thrumming with warmth.

"THERE IS NO NEED TO WORRY, DEAR SISTER. THE GREAT PAPYRUS WILL GET OUT OF THIS ALIVE AND MAKE YOU SOME SPAGETTI WITH THE HUMAN AFTER THIS IS SORTED OUT." He assured, seeming sure of himself. Arial wished she could be that optimistic, but the last time she trusted a human…she shuddered internally at the memory.

"Papy, please." She pleaded, tears beginning to prick her eyes. Papyrus blinked with surprise and his shoulders sagged with defeat. He nodded silently and Arial breathed a sigh of relief, dragging him away from the misty path. Papyrus glanced at it for a few seconds, then his white irises landed on her.

They finally reached their wood cabin in a couple of minutes, Arial stepping into the house and running her fingers through her hair. She breathed in a couple of times, trying to get the image of the human out of her head. She had one less brother to worry about, but Sans was still out there with that thing. Saying she was worried was an understatement…

Papyrus sensed her worry and pulled her into a hug, his eyes lighting up a soft orange. Arial felt relief wash over and she wrapped her arms around him, allowing him to lift her up and cuddle her. Eye glowing was an effective way they used to calm each other down. The warmth that spread through her SOUL was welcomed.

"I LOVE YOU, LIKE A TEMMIE IN A CUBE,

LIKE THE RUINS RUBBLE HEAP AND

NEW HOME'S CROWDED STREET.

I'D LOVE YOU THROUGH SNOWDIN AND WATER FALL,

AND THE LAVA'S STEADY CRACKLE

NOW, I'M TALKING IN MY SLEEP

ABOUT YOU!" He sang softly. As if an invisible string was tugging at her eyelids, Arial felt her eyes close, surrounded by the comforting humming and warmth. In her hazy vision, she saw Papyrus lay her on the couch, a look of apology on his face. she unconsciously reached out, tugging at the black fabric of his sleeves, groaning with protest. Finally, sleep took over her.

It was a mistake.

When she woke up, she noticed Papyrus wasn't around the house and leapt to her feet, stumbling out of the door, panic rising to her throat. There was a note taped on the wall with Papyrus's uppercase lettering spread across it haphazardly like he was in a rush when he wrote it. She scanned its contents, face growing pale and her fingers numbing. The note fell to the ground, swept away by the wind as she took off, tears falling down her cheeks.

DEAR ARIAL AND SANS (IF YOU'RE THERE),

Arial leapt over stray rocks, her sobs filling the air.

I TOOK TO MIND THE STRANGE BEHAVIOUR THE HUMAN EXHIBITED WHEN YOU POINTED IT OUT AND I WAS…DISTURBED. THE POOR THING MUST BE TERRIFIED AND SCARED IN THIS NEW PLACE, FAR FROM HOME. I THOUGHT OF ARIAL THE MORE I CONTEMPLATED OVER IT AND HOW SHE WOULD FEEL SURROUNDED BY HUMANS.

She tripped, falling into the snow. Picking herself up, she didn't bother dusting away the white powder, continuing to sprint towards the outskirts.

I THINK THAT SPEAKING TO THE HUMAN AND TRYING TO CHANGE THEIR MIND WOULD BE A BETTER OPTION. IT'S NECESSARY TO TAKE SMALL STEPS…I HAVE TO ADMIT, I'M A LITTLE SCARED. I'M SCARED THE HUMAN MIGHT NOT COOPERATE AND…

NYEH! LET'S NOT THINK ABOUT THAT. I HAVE DECIDED TO GO AFTER THE HUMAN AND HELP THEM, YOU SEE. WHEN I COME BACK HOME, THE GREAT PAPYRUS WILL PROBABLY HAVE A NEW FRIEND WITH HIM!

She stopped, hands clamping over her mouth when she saw Papyrus standing before the bridge, body gradually disintegrating into dust as he fell.

"B-BUT STILL! I BELIEVE IN YOU! YOU CAN DO A LITTLE BETTER, EVEN IF YOU DON'T THINK SO!" he exclaimed, blood and dust intermingling together. No sound escaped her throat as she fell to her knees, silent sobs escaping her mouth.

AFTER I BELIVE IN THE HUMAN, THAT THEY CAN CHANGE TO A BETTER PERSON. AND I KNOW DEEP DOWN, DEAR SISTER (AND BROTHER), YOU DO TOO! DON'T YOU WORRY NOW. THE GREAT PAPYRUS WILL RETURN!

His body was mostly gone, but he still managed out a weak smile.

"I…I PROMISE!" he whispered.

I PROMISE.

The brother killer stared at their dust for a moment, then went on, not bothering to look back to her hunched body. Arial choked helplessly, picking herself up and tripping towards Papyrus' remains, his dust piling up around his red scarf. She picked it up gingerly with her shaking hands, a new wave of tears pricking her eyes.

Gone.

He was gone.

She buried her face into the warm material, body convulsing with her cries. She felt desolate, terrified…Papyrus didn't deserve this. What was the human thinking? What was she thinking?! Why did she just stand there, watching like an idiot? Why didn't she move? Why didn't she fucking move?! Papyrus would still be alive now!

It was all her fault. Her fault!

She didn't know how long she was hunched, face hidden by her bandanna. When she felt a hand over her shoulder and Sans' familiar hum of magic, Arial let out a dry sob, arms wrapping around her oldest brother. Sans seated himself behind her, eyes now an inky black, unlit by the glow of his irises. He held her close, letting her cry into his shoulder.

"It's my fault." She sobbed. "It's all my fault."

"Hey, don't blame yourself." He coaxed. "I should have been there with you, but like a total idiot, I hung back. I'm sorry, Ari." She looked up, sniffing softly. Her white irises had shrunk into a blank, half dead stare. She then gazed at Papyrus' red scarf in her hands, which was partly covered with dust, then at his remains.

"I have to stop that brother killer, Sans." She whispered, rage beginning to boil in her SOUL. Sans' eyes shrunk with panic. "I can't let them kill anymore innocents."

"Sis, let's leave it to Undyne. She'll probably handle it." Sans pleaded, desperation in his voice. Arial turned a deaf ear, looking down the path at the bridge. She needed to stop them. That brother killer could tear more families apart…

"Undyne isn't invincible, especially with that unstable amount of DETERMINATION." She cut in. shutting her eyes, she recalled every monster they killed in cold blood, leaving their dust behind. She saw Papyrus falling over, arms still open to welcome them in, to comfort them. They murdered him. "I can't sit around, you KNOW that Sans." She opened them once again, a green flame glowing on her good one.

Sans let out a tired sigh, collecting the scarf from her hands and wrapping it around her neck, with her striped one. He paused for a moment before replying. "I know. I can't stop you anyway, sis."

Arial nodded briskly, getting to her feet. Sans watched her walk down the path, red and green striped grey scarves blowing behind her. He watched her break into a sprint, leaving a flurried trail behind her as she kicked up snow. He watched her figure disappear into Waterfall's entrance. Then he sighed once more, shutting his eyes and slipping into a shortcut.

"Papyrus is dead?" Undyne repeated with shock and disbelief. She glanced down at Arial with a wide eye, looking for any form of falsehood. Arial stared back, wiping away any more tears, her eyes puffy from all the crying. She nodded silently again, allowing the fish monster to digest the information. Anger flashed through Undyne's face and she donned her helmet, hiding any more of her emotions.

"That human's dead." She hissed. "I'll end their miserable existence for dusting him, that's what I'll do. There's NO WAY I'm letting that demon hurt any more innocent people." Arial pursed her lips. She and Undyne shared the same SOUL trait and was briefly trained by her to harness green magic. She liked the loud fish, but with the rage that seeped out of her, she made sure to keep a small distance between them.

"But first, I need to tell Alphys to evacuate everyone." Undyne decided. There was a faint sound of grass shifting and Arial let out a sharp gasp, the two female stiffening. The fish monster walked forward a few steps, eye narrowed dangerously as a teal spear materialized in her hand. She watched for any sign of movement, Arial's own eye darting around the grass. She was gently pushed back by Undyne, the shadows covering them.

"Hey, you need to leave too." The fish stated. "I'll hold off the human, help Alphys evacuate, okay?" Arial nodded silently, taking off towards Hotland, legs pumping as she stepped over slush and marsh. She didn't stop to take in Waterfall's beauty, with its luminescent waters, the glowing Echo flowers or the star studded ceiling.

Wading through murky water, her arms brushed against a few of the cyan blossoms, soft words whispering into the air. She didn't stop to rest, scrambling over wood, then wet dirt and finally dry mud, heat surrounding her, until Alphys' lab loomed before her, a large white and box-like structure that stood firm on Hotland's ground. Arial paused, looking to the side where the guards One and Two were stationed. Pulling out her cellphone, she called Alphys from her contacts, body shaking.

"H-hello?" the yellow saurian monster replied.

"Alphys, do you have any intel on the human?" she asked quickly. There was furious muttering in the other end and a short stretch of silence. "Y-yeah. When U-undyne c-called to e-evacuate the civilians, I-I put m-more tabs a-around t-them. T-they're o-on the bridge r-right now a-and…" Stillness. "O-oh g-god!"

"Alphys, what is it?" Arial asked, voice quivering with panic. "What wrong?" Alphys simply wailed, sobs tearing out of her throat. The line then went silent, Arial still holding the phone to her ear. Her irises had disappeared and her body began to convulse with panic. A dry chuckle escaped her throat, then another, tears beginning to roll down her cheeks.

She turned to One and Two. The guards were watching her silently, yet they did not move from their places dutifully. She walked up to them, pausing, waiting for them to step aside. They did, allowing her through. She ran her fingers through her hair with agitation, looking ahead.

The mural she was working on at the core entrance was splayed behind her. Arial stood there, her fists clenched as she waited for the brother killer to arrive. It wasn't a bad painting, Asgore permitting her to vandalize the wall all she wanted. There was currently a pair of wings, one a deep blue and the other a pristine white that was painted on, against an unfinished black galaxy background. There were a few stray bottles of spray paint still lying around here and there, a few snitched by the local high school kids who wanted to do something cool.

Footsteps echoed through and Arial stiffened at the appearance of the human who had more dust all over their body. She watched them take a few more steps forward, then stop at the sight of her. They let an insane grin spread across their face, holding up the knife almost mockingly.

"So, you've c-come this far, huh?" she mused, her voice trembling. "That's n-not much of a s-shock." She added, looking down for a moment, then back up at them.

"I really want to believe you c-can change kid." She mumbled. "I really do, but y-you've killed too many monsters t-to feel any more remorse. LOVE, no, not love. Do you know what t-that means? It's not a joke. You can't really treat this lightly." the human took another step forward, the unsettling smile still on their face. Arial blinked, SOUL panging with anxiety. She shut her eyes, Papyrus' dust on the snowy ground floating in her mind. She opened them and glared straight at the brother killer, indescribable rage filling her system.

"Fuck the pleasantries." She snapped. "I won't let you kill any more people, you filthy killer, you hear me? Screw my fear, my insecurities, because right now…" The room darkened, as they resumed a monochromatic hue. The mural had turned into a simple green outline behind her. Arial felt her magic rise to her right eye and blaze out, the emerald flame swirling hypnotically. She pulled their SOUL out, the red heart now splotched black with LOVE.

"… ' u."

Her theme blasted around them, a faster pace of Sans' usual slow and lazy melody that had started with a record swiping and a small drumroll. There was a wave of trumpets and she turned the SOUL green, sending a barrage of bones at them, each of them hitting with the beat. The human blocked them with ease, eyes burning.

A few more bones were sent out in her regular pattern, the Gaster Blasters accompanying with a hum and a burst of pure energy. The human skidded back, clothes scorching before they ran forward, swinging their knife. Her theme took on a small segment that resembled Papyrus' melody, Bonetrousle at this point and her insides panged.

*Arial.

3ATK, 2DEF.

*A weakling, just like her brother. Just get this over with.

"Weak?" Arial repeated with malice. The flame in her eye sparked purple and she sent a wave of bones with a mild purple tinge to it. The brother killer paused, one of the attacks grazing their cheek, a few drops of blood bubbling out. The effect of the Karmic Retribution knocked out a good number of HP from their stats. "How's that for a weakling, demon." She hissed, a small grin spreading across her face.

Her fur hood fell back revealing her messy mop of dark hair. her magic crackled through the atmosphere, sending out a smell of burning calcium and paint.

Arial could feel her stamina wane as she sent another blast. Her attacks had slowed considerably and her legs shook with the strain of having to support her body. Sighing, she nearly fell to the side, but steadied herself, just in time to dodge a stab from the brother killer. She had taken a few hits, but not to an extent where it was life threatening. While her HP had decreased since the incident it wasn't to the extent where it was dangerously low like Sans'.

"Give up, please." She pleaded, choosing to ACT this time. "Kid, killing everyone isn't worth it. We could have been friends if you simply asked for love." The human paused at that, expression hidden by their hair. They gritted their teeth and lunged forward, this time landing a hit and knocking out some HP from her. Arial coughed into her sleeve, red staining it.

"Fine." She hissed, pushing away the déjà vu. She summoned her special attack, two rows of Gaster blasters that surrounded the front and right of the human. One Gaster Blaster from each row let their eyes flash cyan, signaling a blue attack and the brother killer scrambled into their crossfire, staying still as the beams shot out, crossing in with each other. The blue attack phased right through them.

Arial blinked. She was sure, deep in her subconscious that she had gone through this before.

The knife swung in a deadly red arc and Arial fell back, spewing out blood. She landed on her back, then groaned, her body slowly disintegrating. A crack ripped through her good eye and she curled up, her bleary vision focusing on the brother killer above her. They walked a few steps forward, then drove their foot into her waist, sending up a shower of dust. Arial screamed with agony, body sent into a painful spasm.

The brother killer then proceeded into the CORE, hair hiding their face.

Arial was half dusted when Sans ran into the scene, eye wide and frantic. When they landed on her, his white irises shrunk and despair washed over them. He stumbled towards her, getting on his knees and holding his hand above her, shaking, like he was afraid to touch her, lest she shatters.

"Nonono, Ari, I'm so, so sorry." He whispered. "I tried to get her quicker this time. I TRIED." His shoulders trembled slightly. Arial blinked sluggishly, her hand reaching up and poking his cheek. Sans tensed, lips pressed into a straight line.

"S'okay." She slurred, her SOUL's beat fading quickly. "I f'give ya'." Her eyes shut as the rest of her body crumbled into white ash. Her SOUL, a small upside down heart that was lined with a large crack on the left half floated before him for a few seconds before it broke apart and faded into oblivion. Sans gritted his teeth, tears beginning to trail down his cheeks. He eyed the striped green bandanna and the bright red scarf left behind and picked them up gingerly.

He wrapped the scarlet muffler around his neck and tied the green fabric on his forearm, getting to his feet and hutting his eyes. When he opened them again, he was in the last corridor, sunlight streaming into the hallway. A fire was lit in his eyes as he absentmindedly gripped the cloth of his blue jacket.

He was DETERMINED.

The human drew their knife when Sans came into view and grinned with malice.

Perfect.

Now all they have to do was get past the damned comedian and finally take Asgore's SOUL. They could finally get out of this shitty hole once and for all. Stepping forward, they idly brushed some dust out of their purple sweater and eyed Sans. As usual, he stood there, his grin now forced and sinister. He glanced to the side for a moment, then back at them.

"So, you've been busy, huh?" he chuckled mirthlessly. The human noticed his tedium and gripped their knife unconsciously. For a good number of resets and incessant genocides, they suspected Sans knew something about their power. However they couldn't really prove their notion. Honestly, that possibility scared them.

He sighed, smile dropping. "Hey kid, let's just cut to the chase. I know you suspect my ability to remember and we went through this song and dance before." The human froze at his words, the room suddenly darkening and their SOUL being ripped out of their body. The sudden weight of blue magic fell on them and they gritted their teeth, knees bending at the strain. A few bones erupted from the ground, earning a strangled yell.

"Let's just get to the point." He snarled, his theme, a fast paced and very un-Sans like tune blasting in the background. "Because I'm d o n e."

A grin spread across their features.

He dodged to the side again, snickering softly.

"What? This must be the 655th time you've died on me in this timeline? That's an unlucky number of times, kid." He insulted, sidestepping, allowing them to hurtle past him. He gripped their SOUL with his magic again and threw them against the wall, a few more bones erupting from the marble surface. Their SOUL cracked again, giving Sans a few more seconds of respite before the human reset again.

"This is the 656th." He reminded, sighing softly. "Hey, hold up a moment." He stated, stopping them in their tracks by raising a hand in temporary truce. "Before you go all genocidal again, I just wanna ask you something." He shut his eyes, the opened them again. "Why did the chicken cross the road?"

The human faltered and he took advantage of their disorientation and sent another bone through their SOUL.

"Heh, 706th reset." He mused. He let out a short breath of air, watching the human come at him with another swing of their blade and he stepped aside again. Pausing, he activated his blue magic, left eye flaring up a brilliant cyan flecked with yellow and grabbed their SOUL. However this time, he didn't send them through a wave of elaborate attack patterns. He simply stood there, contemplating idly.

"You know, I wish I could say I could do this forever." He began, voice thick. "But I can't, do you understand." He inhaled. "Listen, kid, I kind of realize where you come from. You were afraid and all you want to do is go back home right?" he looked at the human who wore a look of shock on their face. Ever-so-slightly, they nodded, eyes wide. "Thought so. Now…uh, correct me if I'm wrong but…" he pursed his lips. "Didn't Toriel offer you a home? She was ready to take you under her wing and raise you as her own kid, right?"

The human tensed at this. They frowned, suddenly realizing that he was right. Maybe through their LOVE muddled mind, they didn't see that, but rather an obstacle.

"You can take this another way. RESET, kid. Go back to the beginning and try another approach. Maybe you'll get what you REALLY want." He continued.

The human faltered, knife slipping out of their hand.

"Not LOVE, but love, right?"

A tear trailed down their cheek and Sans blinked with mild astonishment, letting go of his blue magic. The human fell on their knees and cried into their hands, muffling out any sniffs or sobs. Sans rubbed his arm mechanically, tired sweat beading up on his forehead.

"Huh, kid, you okay?" he asked, taking a few tentative steps forward. The human looked up, face wet and stained from crying. They let out a few hiccoughs and nodded, wiping their nose with their sleeve. Getting to their feet shakily, they sent him a genuine smile. Sans sensed their intentions.

And sighed with relief.

"There's something we agree on." He stated, a less forced grin creeping up on his face. "But, uh, I hope you won't mind what comes next." A bone materialized in his hand. The human stood their ground, a new DETERMINATION in their eyes. They snuck one last look at Sans and took in a deep breath as the bone impaled their chest and they fell back on the marble floor.

Arial woke up in her bed, a terrified jolt shooting up her spine. She hunched over, calming her trembling and let out a tired sob, rocking back and forth to calm herself down.

AIIII, that's chapter one. I'm sorry that it's so long.

So what do you think so far? Please leave a heart, follow and review for this work. I would love to hear your opinions and comments make me so happy!

Updates are once a month. If I manage to finish a chapter faster, I will make sure to upload it asap. I also have a deviantart account where I will upload drawings and any clarifications. The link is in my profile.

See you in oblivion!