(I'm sorry, Frisk is a female in this, but that's just because I prefer them female, and it makes it less confusing to read. Also, I don't know if this is needed, but TRIGGER WARNING for people who aren't comfortable with panic attacks. I do skim over it, but I do not want anyone to be uncomfortable, so a little heads up!)

" THERE YOU GO, DARLING~" Mettaton said as he put the final touches on Frisk's costume, "MY, OH MY, YOU LOOK ABSOLUTELY TERRIFYING!" He shouted with glee as he looked at the finished costume. The costume itself was pretty simple, just a copy of Frisk's beloved sweater, a pair of jean shorts with leggings, and black boots. But the detail added was what Mettaton was proud of. Using his skills in cosmetics, he made Frisk's messy, thick hair filled with small yellow flowers, added lots of product to make their skin a ghostly pale color, made cuts and tears into the sweater and pants, and even added hyper realistic blood where it seemed necessary.

"HMMMM.." The robot pondered, walking around Frisk, studying his creation, "SOMETHING SEEMS TO BE....MISSING." He put his hand on his chin, stopping in front of the child again, resting onto one hip. He cocked his head at the child, wondering what seemed to be making this outfit incomplete.

Suddenly, Toriel came around the corner. She glanced in their direction and gasped, jumping slightly, " Oh my goodness!" She shouted shocked, "You nearly gave me a heart attack! The only thing that could make you any more frightful would be covering you in du--"

" THAT'S IT!!!!" Mettaton shouted victoriously, cutting off the old women, " THANK YOU SO MUCH FOR YOUR HELP, DARLING!" Mettaton chimed towards Toriel in a sing-songy voice.

Toriel raised confused brow at the robot, her muzzle wrinkling slightly, "You're welcome?" She then shrugged it off, before heading towards her room with a yawn, " I'm going to head to bed now, good luck with your prank my child, and I love you." She said, blowing Frisk a kiss.

Frisk giggled at her mom, before signing to her,"(Love you, too)".

Mettaton got straight away to getting some white and grey makeup powder, and putting it all over the child's arms and cloths. After he finished making it up to Mettaton standards, he backed away, once again examining the child.

A smile split across his features, "MY LITTLE STAR," He began enthusiastically, " YOU LOOK PERFECT!" He picked up the child and twirled them around, causing them to squeal, before setting them back down.

He then looked at the clock, his eyes widening in surprise, "OH MY!!! ELEVEN FIFTY ALREADY??!! AS MUCH AS I'D LIKE TO STAY DARLING, I'M AFRAID I MUST PART, I PROMISED ALPHIE THAT I'D WATCH MEWMEW WITH HER AT MIDNIGHT." He quickly packed up his supplies and and threw on his fluffy, red coat.

He stopped at the door as his face lit up from remembering something, "DON'T FORGET YOUR PLASTIC KNIFE! AND LET ME KNOW HOW THE PRANK GOES, MY STAR!" He was about to leave when another thought came forth, causing him to reopen the door, "OH, AND DON'T FORGET TO TELL THAT LITTLE SWEET HEART HAPPY BIRTHDAY AND HAPPY FOOLS DAY FOR ME!" He smiled at the child before waving as he shut the door, "TA-TA~" The door slammed closed, leaving Frisk by herself.

Before heading upstairs to get Papyrus, she quickly darted into the bathroom to look at herself. She grabbed a stool, and brought in up to the bathroom sink, so she would be tall enough to look into the mirror that was above it.

She stepped onto the stool before peering into the mirror, jumping at her own appearance. Mettaton really out did himself, the blood to dust all looked so realistic, however, for some reason,this left Frisk with an uneasy feeling, that she didn't understand. Something about this outfit seemed....familiar. The child frowned at her own reflection, the odd feeling in her stomach not leaving her. She shook it off, pushing the thought to the back of her mind, it probably was nothing anyways.

She hopped off the stool, before placing it back where it came from, she then ran out to the kitchen to grab her toy knife, before running up the stairs into Papyrus' room. Papyrus was sitting at his desk, playing what appeared to be Seven Nights At Stevie's, even though the game was actually nine nights long, making the title make absolutely no sense.

She walked up to Papyrus, tapping him on the shoulder. The skeleton jumped nearly a mile high, before whipping around to see Frisk, then proceeding to jump again, "NYEH!!!" He shouted with surprise at the human's appearance.

"(It's just make-up!)" Frisk signed quickly, letting out a playful giggle.

Papyrus blinked, gathering his thoughts, before he started laughing, " NYEH, HEH HEH, OF COURSE IT IS HUMAN, WHY METTATON REALLY DID AN OUTSTANDING JOB ON YOU!"

Frisk giggled again, before asking,"(Where's your costume, Papy?)"

The skeletons eyes brightened, before he pulled out a sheet, and put it over his head." IT IS RIGHT HERE, HUMAN!" He chimed excitedly.

Frisk raised a brow at the skeletons costume confused. Papyrus took the hint, and quickly said, " IT'S A JOKE BETWEEN ME AND SANS, HUMAN," He explained, " HE USED TO SCARE ME WHEN I WAS A LITTLE BABY BONES LIKE THIS, SO NOW I, THE GREAT PAPYRUS, SHALL GET REVENGE!" He shouted victoriously, pumping his fist in the air.

Frisk let out a little, 'awww', causing Papyrus to now be the one confused, "WHAT WAS THAT ABOUT, FRISK?"

Frisk's face slightly blushed as she signed, "( When you two talk about each other like that it's so cute.)" Papyrus' face scrunched up at this, a faint glow of orange coming off his cheeks.

"IT IS NOT CUTE, HUMAN!" He said, pouting a bit, causing the child to giggle even more, getting an odd satisfaction from his flustered state.

Papyrus frowned as he shook his head, closing his laptop, " W-WELL," he began, still recuperating from his previous fluster, " THAT'S ENOUGH OF STEVIE FOR TONIGHT, NOW LET'S GO SCARE MY BROTHER OUT OF HIS SKIN!" he said excitedly, not being able to hold back his glee of his clever prank. After all, Sans' birthday fell on April Fools, which was now only a minute away, why not shake him up with a little scare to start the day. Even though Frisk doubted that he was even able to be scared, seeing as things that most people found scary, didn't even phase him.

The duo quietly tiptoed up the hallway, making their way to Sans' room door. Papyrus slowly opened the door, letting both of them walk in together. They crept up to the side of Sans' bed. The smaller skeleton was sleeping soundly in a curled up fetal position, his arms seeming to be hugging onto his under-sheet. Both Frisk and Papyrus snickered.

Papyrus whispered, in what most people considered a normal talking level, " Three....two....one!"

Both the child and monster let out a yell, startling the small skeleton awake, making him snap into a sitting position.

"Wh-wha?" He said quickly, confused, his eyes half open from his drowsy state. He quickly turned to the side, first making contact with his brother. He rubbed his eyes before groggily saying, "papyr--" he cut himself off as his eyes fell on Frisk. His eyes suddenly snapped open, wider than the child thought possible, as she saw something glitter in his eyes, she hadn't seen in anyone else's....fear. In that moment, she suddenly realized, he was afraid of her.

His eye lit up with a cyan blue glow, traces of buttercup yellow licking at the sides of the flame. Frisk felt a grab on her soul, and before she could react, she was being hurled at a wall.

Papyrus, having a quick reaction time, despite it being the middle of the night, quickly grabbed his brother's wrist, forcing him to release the child's soul, causing her to smack into the wall with much less force than was initially intended.

" BROTHER, STOP!" Papyrus shouted, his grip on his brother's hands like iron.

Frisk scrambled up to a sitting position, leaning against the wall for support, her chest rising and falling quickly from the rush of adrenaline, quickly signing, "(sorry)",over and over again.

Sans' eyes darted between Frisk, his brother, and the knife Frisk had dropped, in a confused, almost hysteric state. The flame in his eye slowly died down as he began to put together what had happened.

"They didn't mean it, Sans," Papyrus began in a soft voice, releasing his grip on his brother's right wrist so he could take off the sheet on his head, immediately catching his brother's attention, who seemed to be holding in his breath, "It's all fake, and MY idea."

Papyrus felt a sudden shudder go through his brother, as he kept staring at the child curled up on the floor, his eye-lights suddenly flicked to the knife. A strange, almost high-pitched sound, like the sound from a tea-pot, escaped the smaller skeletons throat, as his eye-lights dissipated, leaving empty, black voids. He suddenly started trying to suck in air, as if something was strangling him, as he spazzed, ripping his other wrist from his brother's hand, and scrambled into the corner of his bed frantically. He grabbed his own skull, his knees quickly pulling themselves to his chest, as he stared off into nothingness, his breath not coming normally, creating a wheezing sound.

Papyrus quickly came over to his brother, grabbing firmly onto his shoulders, "Sans look at me!" He demanded, worry and regret tracing his voice, however, the smaller skeleton quickly yelped, squirming away from his brothers touch,curling up around himself on his mattress, making himself look even smaller than he already did.

Frisk quickly stood up, dashing out of the room.

Your fault, your fault, your fault

They fell against a wall in the hall, their breath labored from the confusion. What had just happened?! Why did he respond like that?! Why was he afraid of me!? Were the only thoughts buzzing through the child's head. It was just a--

"Prank?" A shrill voice said, echoing around the small girl. A giggle erupting from its owner, " Oh, Frisky, how could you forget, yet a creature with less than half your determination remember?"

Frisk's head snapped around, to see another child standing next to her, skin as pale as snow, with bright red rosy cheeks. Frisk's hands shook as she signed, "(who are)--" She was cut off.

"Don't you remember me, partner? My name is Chara." The name split through Frisk's skull, sudden memories flooding in. Screams, cries, begs, pleads, warnings....d u s t. Frisk felt her body begin to shake.

"Oh, so...you DO remember the good times." The child said, a wicked smile cracking her cheeks.

"S-s-stop." Frisk's voice was below a whisper and hoarse from never using it.

" Oh, what's the matter Frisky poo? S C A R E D ? !" Her features suddenly melted into a black ooze that ran down her face. "It was allllll, your fault Frisk. You killed them A L L. Crushed their hopes, killed their family....killed Y O U R  F A M I L Y."

" ST-STOP!" Frisk yelled, her voice croaking from the tears that were pouring down her face. She remembered it all. Their faces, their grief, their tears, their screams, their broken hearts. She remembered her mom, fading away to a pile of dust as she came to the realization too late; she remembered Papyrus, still seeing good in her as she stomped his skull to dust; Undyne as she slowly, painfully melted, believing that she had failed everyone; Mettaton as he gave one last attempt to save humanity and all his friends that were still alive; then she remembered Sans' broken face, as he tried to stop her, warn her of what was going to come, and get revenge for the brother and friends he had lost all in one day. She remembered every. single. second. She remembered how many times he had obliterated her, hoping that it'd finally be the last time, only for her to come back, again, and again, and again, until she finally tired him out, and sent a blade straight through his rib cage.

"Oh, poor lil innocent fwisk," Chara said in a baby voice, "what? Is the comedian making you sad? Or is it his idiotic brother? Or the rest of the of them?"

"Shut. Up." Frisk seethed, trying to get the images out of her head.

She giggled, " Oh but Frisk, you haven't even heard my offer."

Frisk remained silent, ignoring the girl.

" I know how to make all that pain go away," She reached out her hand to Frisk, " just take my hand, and it will all end." Her eyes widened, a soulless red glow radiating off of them.

Frisk glared at her hand. But she refused to take it.

Chara looked down at her, a frown gracing her features, "hmph," she began, "fine, be that way, but....I will be back Frisk...and next time... N O  M O R E  M I S T E R  N I C E   G U Y." Her voice seemed to echo through the hall, before it eventually began to dissipate into nothing more than a ring in Frisk's ears.

And with that, the demon vanished.