AtonemenTale

Chapter 1

Oh boy! Here we Go! From what I'm given to understand Undertale is attracting some weird crossovers well let's see it get weirder than THIS. This is really in honor of my sister science it's close to her birthday and I know she loves Undertale so I decided to write a story about it. Thing is I'm not a Undertale person so I had to put in characters I really like to keep me motivated to write. At first I had an interesting idea for foreshadowing something for the Fates of S.T.E.A.M. involving Robin, then I had a urge to write something about Sonic soooooo here we are. Please don't hate. I do not own Undertale, Fire Emblem or Sonic the Hedgehog or the characters.

Chapter 1: Megalomaniac

"I don't want to do this…"

"Sure you do! Why did you RESET in the first place? Because you were bored that's why! Now look at all the fun we're having!"

"Mom...Papyrus...Undyne...Everyone…"

"Oh, get over it already! Flirting with everything to solve all your problems is disgusting anyway! Now hurry up and kill that stupid comedian already!"

"No! I already lost so many friends!"

MERCY

"you're sparing me? finally. buddy. pal."

"Sans…"

"What on earth are you doing?"

"i know how hard it must be…to make that choice. to go back on everything, you've worked up to."

"I'm sorry…*sniff* I ruined everything…"

"Correction: You're about to ruin everything you dolt!"

"i want you to know...that I won't let it go to waist."

"Sans, please…"

"Kill him!"

"...c'mere pal."

…

STAB

"…Thank you…Sans…I'm sorry..."

"geeettttttt dunked on!"

"Good bye…"

"You freaking idiot! See what happens when…wait what are you…"

"if we really are friends…you won't come back."

"I…I won't…I just need to-

"Oh, I see what you're up to! You did that knowing he would kill you so you can reset!"

"Wha-why can't I...?"

"Heh, he, heh…You seem confused…"

"Huh?"

"DID YOU SERIOUSLY THINK YOU WERE THE ONE IN CONTROL?"

"What do you mean?"

CONTINUE

"No…"

"Yes."

…

"heya. you look frustrated about something."

"You don't know the half of it you, stupid skeleton."

"Please, don't do this!"

"guess I'm pretty good at my job, huh?"

"If you don't want to kill him then just get out of the way and let me!"

"Please!"

"it's a beautiful day outside."

"Please…"

"birds are singing, flowers are blooming…"

"No…"

"on days like these, kids like you…"

"No!"

"Should be burning in hell."

"NOOOOOOOO!"

Chrom opened his eyes to find himself in a place he had never seen before. He sat up and rubbed his eyes to make sure he wasn't dreaming.

"Well, one of you is awake."

He quickly turned around.

"Hey."

"Robin? Where are we?"

"Question of my life." The tactician sighed. "I just remember finishing my studies and next thing I know I woke up here."

"Are we the only ones here?"

"No." Robin replied pointing to Lucina, Morgan and Lissa slumped against a wall. "Don't worry they're just asleep. But what's really bizarre is who woke me up."

"What?"

"Oh, hey! One of your pals is up."

Chrom turned around to see who…or rather what was behind him.

He saw some blue creature with spikes on the back of his head wearing white gloves and red shoes.

Chrom just stared trying to process it.

"Not much of a talker, is he?"

"Er, who and what are you?"

"What? Never seen a hedgehog before?"

"What? Hedgehogs aren't blue! And they certainty can't talk!"

"Well maybe this one can!"

"Robin…your seeing this right?"

"Sure am. And hearing it." The tactician shrugged. "Now believing it, that's another matter entirely."

"How much did we drink today?"

"I don't drink remember? Well, judging how well your memory servers you I'd say you had a few."

"Oh, right. Because you take literally everything too seriously." Chrom said rolling his eyes.

"One of us has to."

"So are you two just gonna talk to each other or are ya going to interduce me?"

"Oh, sorry Sonic." Robin said. "This is Chrom, the Exalt of Yilisse."

"Nice to meet ya sire! I'm Sonic! Sonic the hedgehog!"

"Er, greetings."

"Hey, Sonic, what's going on?" a voice asked from another room.

"Hey Tails! One of Robin's friends just woke up!"

A creature with two tails a red creature with spiked gloves and a pink creature with a red headband walked in.

"Oh, hey there." the two-tailed creature smiled. "Your Chrom right? Robin told us all your names."

"And you are?"

"I'm Miles Prower. But everyone calls me Tails."

"I'm Knuckles the echidna. Just call me Knuckles." The red creature said.

"And I'm Amy Rose." The pink one greeted.

"It's a pleasure everyone…but is it alight if I ask where we are?"

"Wish we knew." Knuckles shrugged. "We all found ourselves in this strange lab just like you. Your buddy there just got up a few minutes ago. From what he said every one of us are in the same dumpster."

"Speaking of everyone, what happened your other friend…Shadow was it?" Robin asked looking back at the group.

"He went to keep looking around." Tails said.

"Ugh…"

Everyone turned to see Lucina start to stir.

Robin walked over to her and lightly rubbed her shoulder.

"Lucina, wake up."

"Mmmm…Robin?"

"You okay?"

"Where…"

Lucina then immediately notice the strangers next to her father.

"Wh-What are those things?!"

"Hey! Who are you calling things?!" Amy pouted.

"Look at it this way: Can you sincerely say that this is the weirdest thing we have ever seen?" Robin smirked.

The princess calmed down a bit at the thought.

"Well if you put it that way…"

"Not so loud…"

They then notice Lissa and Morgan waking up.

"Father? What's going-

Morgan stopped in mid-sentence looking at Sonic and his friends.

She and Lissa stared in disbelief.

"Oh, boy." Chrom sighed.

"Chaos Spear!"

BOOM

Shadow blew down a locked door and entered a large room filled with monitors. The black hedgehog scanned the area.

"Looks like a surveillance room…"

He found a key pad and pressed a few buttons. The screens changed showing a snowy area, a waterfall, a rocky area surrounded in flames and even a dark cave that had what looked like stars. But one thing stuck out in all of them.

"It's not just this building…every place that's being monitored has nobody in it. What's going on here?"

He kept looking until he found a strange hall.

That's when he finally found someone.

There was a young girl with brown hair and a blue shirt with a purple strip and what appeared to be a skeleton in a blue jacket.

"What?"

He couldn't make out what the skeleton was saying.

"listen. friendship…it's really great, right?"

"It is…It really is…"

"Oh, please.

"let's quite fighting."

"I really want to…"

MERCY

"I won't stop until I get rid of him you know. And until then you can suffer the pain of your dear friend killing you over and over."

"Fine…all the pain…all the insults…I deserve it for what I did!"

"Green Hill Zone? What's that?" Morgan asked.

"Where we were hanging out before there was a burst of light that sent us here." Sonic shrugged.

"And you guys never heard of Yillise?" Lissa asked.

"Nope."

"Something tells me we were sent to another world. Again." Robin sighed.

"Well what a coincidence. Not our first time either." Sonic joked.

"Than what-

Before Lucina finished her sentence, everything went black.

When they opened their eyes, they were all slumped against the wall again and Sonic and his friends were on the ground. A black creature that looked like Sonic was with them now.

"Ugh, not again." Robin groaned.

"Hiuh? What was that?" Morgan asked.

"No idea. Suddenly everything goes black and then everything is the exact same as when we first woke up here." Tails said. "It happened quite a few times now."

"Dang it!" Knuckles grumbled punching a dent into the ground. "What the heck is going on?!"

"Easy there pal." Morgan said. "Some of the stuff here looks breakable."

"So, that's what's going on!" The black figure said getting up.

"Oh, hey Shadow." Sonic said to the newcomer. "All of Robin's pals woke up. Guy's this is Shadow."

"Uh, hi." Lissa said "My name-

"I know who you are, Robin told us." Shadow said. "More importantly I found something."

"Really? Lead the way." Robin said.

"It will take too long to get there. I'll just use this."

"Use what?" Morgan asked.

Shadow held up a red gem.

"Chaos Control!"

In a flash of light they were all transported to the surveillance room. Shadow looked at the door he blew down. It was perfectly intact like it never happened.

"I knew it."

"How did you do that?" Robin asked.

"And what's that gem for?" Lissa asked.

"That's a Chaos Emerald." Sonic said. "Each one gives you slight control over time and space. If you get all seven you can unlock infinite power."

"Incredable." Lucina said. "They sound like the five gemstones."

"Soooo, what did you want to show us?" Knuckles asked.

"Over here."

Shadow led them to the control and starred pressing buttons.

"Didn't Henry's world have this?" Lucina whispered.

"Yeah. Back at Buckingham Palace." Robin replied. (See Code Name FE Ch 4)

"Tails, can you do somthing about the sound quality?" Shadow asked.

"I'll give it a try."

Soon Shadow brought the monitor to the hall he saw earlier.

The others gazed at the figures in them.

"Is that...a skeleton?" Amy asked slightly paniking.

"That kid..." Robin said.

"She...she looks like Morgan..." Lucina said.

"Hold on...there!" Tails said after tampering with some wires. "Sound should be on."

"hmm. that expression…that's the expression of someone who died eleven times in a row. well give or take."

"I assure you it would be a lot less if someone would stop taking control at the last minute to offer mercy with the reply being you killing us! Hint, hint!"

"I won't let you…Sans is all I have left!"

"there's nuance to this stuff. Don't think I'll be able to count very well from here. count for me, okay? we'll start at 12."

The girl held a knife in their hand.

"it's a beautiful day outside. birds are singing, flowers are blooming…on days like these, kids like you…Should be burning in hell."

A red heart appeared on the human's chest as she rushed at the skeleton but he dodged the attack. Suddenly the heart turned blue and she was flung into a wall. When she saw the skeleton's eye turn glow they jumped to the side as a bunch of bones rose from the ground beneath her. The skeleton then spawned a oddly shaped skull that shot a blue laser out of it's mouth.

"What the heck is that?" Sonic asked.

"So that girl is being attacked by that creepy skeleton?" Lissa asked.

"That's what I suspected at first." Shadow replied. "But looking closely you can tell that he seems reluctant to fight while the kid is actively trying yo kill him..."

"No kidding." Sonic said as the watched the girl swing the knife. "This kid's out for blood! For somthing that doesn't even have blood!"

"Wait, look." Morgan said.

MERCY

Suddenly the girl dropped the knife to the floor. Their once red eye's turned hazel.

Robin took good note of that. It reminded him of somthing.

"you're sparing me? finally. buddy. pal. i know how hard it must be…to make that choice. to go back on everything, you've worked up to. i want you to know...that I won't let it go to waist."

"Oh, good! Sounds like they decided to stop fighting!" Morgan said.

"...c'mere pal." the skeleton said opening his arms.

The human ran right into them as they embraced her.

"Well, that's over." Knuckles said.

"No."

STAB

Before anyone could question Shadow the child was skewered by bones from the ground.

"geeettttttt dunked on!"

The heart on their chest shattered.

"if we really are friends…you won't come back."

"Well...That killed the mood." Lissa said trying not to look at the blood spewing out.

"How could he?! She surrendered...discarded her weapon and he just killed her when she was defenseless!" Lucina said in shock.

"She's coming back." Shadow said.

"How? Look at her! The poor girl was just impaled in at least six different places!" Chrom said.

"Uh, Chrom?"

"What?"

Robin pointed back at the monitor where they saw the girl's body disappear. Then a rectangular flat shape appeared. The writing on it said RESET.

"What is-

Before Sonic could finish asking everything went black.

Then they all found themselves in the same room as before.

"Again?" Lissa grumbled. "What's doing that?"

"You just saw it." Shadow said. "I don't know how or why by every time that kid dies time resets."

"Wait, time resets? What do you mean?" Amy asked.

"Notice how we always end up in the same spot we woke up in and in the same position?"

"That could just be a coincidence." Morgan suggested.

"Not so. Look." Robin said pointing to the ground.

The others stared in confusion.

"Is somthing wrong with the floor?" Chrom asked.

"What's wrong is that nothing is wrong with it!"

"Context please?" Sonic said.

"Didn't Knuckles punch a dent in the floor when we last ended up here?"

"Hey, your right!" Tails said. "It's gone!"

"There's more." Shadow said. "When I first entered the surveillance room it was locked so a had to blow the door down. But when I sent us there with Chaos Control it was still in one piece."

"So that kid can control time?" Lissa asked.

"Maybe she also has one of those Chaos Ruby things." Morgan said. "You said earlier you can control time with them."

"Chaos Emerald not Ruby." Amy corrected.

"Are you sure? It looks ruby shaped to me."

"More importantly no it was not." Shadow said. "Chaos Control can only slow down and freeze time, not rewind it."

"Wait, if time re-winded how can we remember the events that happened prior to it?" Robin asked.

"Judging from what the skeleton said he remembers to." Tails said. "Did all they're fights go like that, because if they did then we're stuck in a infinite loop."

"I only saw one other besides the one we saw earlier." Shadow said. "But it did end differently. The human was closer to winning before they gave up this time..."

"Did the last fight end the same way?" Chrom asked.

"Yes. She offered the skeleton mercy but it ended with him killing the her. After that it all resets."

"So they just keep retrying the battle?" Morgan asked. "Talk about a sore looser."

"I don't think she wants to fight Morgan."

Everyone turned to Robin who was lost in thought.

"What do you mean? You saw the way she fought." Knuckles said.

"Yeah, but then why would she keep trying to offer him mercy if she knew he would just kill her?"

"Good question." Sonic said with a hand on his chin. "You'd think after 11 times she would take the hint."

"Also...she seemed to be crying when she gave up..." Robin said. "And she...smiled when she was killed...not In the same way she was when fighting him...while doing that she seemed like someone else entirely."

"That look in you're eye says you're catching on to somthing." Chrom said.

"Chrom...do you remember when we fought Validar?"

"One of the many things I wish I could forget."

"Do you remember what I asked you to do if I fell under his control?"

Chrom sighed.

"You asked me to cut you down before you could hurt someone."

Sonic and his friends stared at the two.

"Um...Sounds like good times..." Amy said. "But what dose any of this have to do with...that...kid...?"

That was when the realization hit them.

"Robin...are you saying that someone is controlling her?" Lucina asked.

"It seems possible."

Robin then thought about the red eyes that the child had. And how they changed when she tried to kill the skeleton.

"Those weren't her eyes...what was that?"

"So do you think the kid is doing it on purpose so they don't hurt the skeleton?" Knuckles asked.

"Most likely."

"He doesn't seem to know about this. We'd better warn him right away!" Morgan said.

The others nodded.

In what seemed like a place filled entirely with darkness the girl stared at a button that said MERCY.

Tears shed as she thought about all the monsters she killed. The monsters she once freed. The monsters she once called friends.

She sadly smiled as she reached for the button.

"This is my punishment...It's what I deserve."

"I can't let you do this anymore partner."

Sudenly a black tendril wraped around her wrist.

She turned around to see another child. She had brown hair like hers but her shirt was green with a yellow stripe.

"C-Chara?"

"You have been calling the shots for far to long. Now I will decide how this ends."

Another tendril grabbed the child's other arm and she was pulled away from the button and deeper into the darkness.

"No! Stop!"

As she was pulled deeper in more warped around her body.

"Don't!"

Chara laughed as they walked to where the child was standing. There were other buttons. But she only cared about one of them.

FIGHT

Back in the hall Sans held his arms out but waiting for the human's response.

But this time she charged taking another swipe at him.

MISS

Sans barley got out of the way in time.

"welp. it was worth a shot"

The human's eyes turned red again.

"No, no, no, no!"

"guess you like doing things the hard way. huh?"

The human-or rather Chara took another swipe at Sans but he teleported away.

She turned around to see Sans with a Gaster Blaster.

As it fired she jumped to the side. She then charged at him again.

Sans's eye glowed blue.

Tails was tampering with a computer they found in the room they woke up in. He had the communication device he and his friends use plugged in.

"Are you done yet?" Lissa asked.

"No."

"How about now?"

"Just hold you're horses your highness. This is the kind of job where rushing it will get you nowhere."

"Well you can hurry a bit, right?" Morgan asked. "Who knows when time will reset again!"

"Just a minute...There! I download all the maps here!"

"So where are they?" Robin asked.

"Uh...someplace called the Judgment Hall. Located in...New Home castle?"

"Pfft. "New Home?" Who named this place, a six-year-old?" Sonic asked.

"Beats me." Tails shrugged.

"I got a better question. What is this place we all got throw into?" Morgan asked.

"All I know is that judging by the heat waves everything here is underground."

"That explains why its so darn hot in here." Amy said.

"Anyway here's the map Shadow." Tails said handing over the handheld device. "Can you get us there?"

"We're going to find out."

"Alright! Let's go!" Sonic said. "I'm ready for adventure."

"Guys, maybe The Exalt and his friends should stay here." Tails suggested. "They have a kid with them after all..."

"Don't worry, we deal with stuff like this all the time. And just Chrom is fine. Formalities don't mean much to me."

"Same here." Lissa added.

"Tails has a point though. Be careful Morgan." Robin said holding his daughter's shoulders.

"Right."

Everyone gathered around Shadow.

"Chaos Control!"

New Home Zone Act 1

Sorry for the bad joke, I couldn't help myself.

"This is the place?" Amy asked.

"It should be." Tails said. "Let's go find that castle."

"This place is huge. Let's split up and-

WOSH

Before Robin could finish Sonic, Shadow, Tails, Knuckles and Amy ran on ahead at quite a high speed.

"...Or you can do that."

"Did you just see that?" Morgan asked.

"Gods! What speed!" Chrom said. "These being have unique talents indeed..."

Sans flung the human into a wall for what had to be the twentieth time. But again they got up and brushed it off.

"huff…puff…alright. that's it. it's time for my special attack. are you ready?"

"Special attack" interesting…Let's see what you got left comedian!"

"Special attack?" Sans already looks spent…and that last barrage of attacks was like nothing I've ever seen…what is he going to…"

"here goes nothing." Sans said calmly.

…

…

*Cricket chirps*

"Well?"

"What's he doing?"

"Waaaaaait a minute…don't tell me…"

"yep that's right. it's literally nothing. and it's not going to be anything either."

"…are you freaking kidding me?" Cara thought.

"S-Sans! You can't seriously be that lazy!"

"Wanna bet? Frankly if anything should surprise us about this it's that he didn't do it sooner."

"heh heh heh...ya get it? i know i can't beat you. one of your turns you're just gonna kill me. so uh, i've decided... it's not gonna BE your turn. ever."

"What?!"

"I get it!"

"i'm just gonna keep having MY turn until you give up. even if it means we have to stand here until the end of time. capiche?"

"You annoying...!"

"you'll get bored here. if you haven't gotten bored already, i mean. and then, you'll finally quit."

"Sans...I wish I could…I wish we I could still be your friend…but now look at me…I'm…I'm…"

Inside the darkens more tendrils gathered constricting the girl.

"Just a Megalomaniac."

And that's chapter 1. If you're wondering why I made Frisk and Chara girls in this, it's because A: I'm given to understand one of them (or both for all I know.) are meant to represent the player and as I said this is for my sister and B: I made all the "avatar" or characters with optional or unknown genders (Robin and Corrin.) Male so I thought this would balance it out. And before any of you ask this won't be a Frisk x Sans fic. I personally view them more on a sibling kind of relationship. And no Frisk x Chara, Frisk x Asriel, no pairings with the Undertale cast. The only paring here is Robin x Lucina. Anyway, this story is short and for the most part completed already, I'm just ironing out bugs. So, updates on it will be frequent. Anyway, please leave a review and I hope you enjoy the rest of the story!