You are a (A/T)

Pick a side? Sounds a lot like Civil War...

"Oh ho ho ho ho! You'll never defeat me this time Sonic!"

"Fat chance of that!"

Even in the middle of a semi destroyed street which Eggman stood at the center of, large robot and all, Tails still rolled his eyes at his blue brother and his terrible puns.

"Sonic please concentrate." Tails sighed into his communicator.

Being in the sky in the Tornado meant there was little he could do in terms of keeping Sonic under control. A few more awful puns later and Eggman attacked in a rage, Sonic being careful to avoid as much damage as possible whilst Tails was air support. Circling around he was able to land several attacks which happened.

"Keep hitting him Tails! You're doing great!"

Circling around again Tails shot the Tornado's lasers landing effective hits, but when the plane was suspended upside down for a fraction of a second he was able to glance into the control bay where Eggman was sat.

Except he wasn't accompanied by just Orbot and Cubot this time, he only caught a glance but he could have sworn he saw a female (A/T) in there as well. Either way there was definately someone else in there with him, someone Mobian. He instantly wondered if she was a civilian but she didn't seem to be struggling, in fact she looked rather comfortable in the control bay...

"Tails! Aim at the legs and then this robots done for!"

Snapping out of his logical thinking Tails snapped back into reality.

"You got it!"

With their combined effort the fight was over in a matter of seconds. But afterwards Tails could find no sign of that second mobian in the control bay. 

~A few days later~

It was a mildly sunny day, not to hot not too cold, a perfect day in Tails' mind to work on the Tornado. Except this time he had a valid excuse to tinker away. Eggman had yet again attacked but his robot had been more powerful this time, meaning the Tornado took quite a beating.

But still, nothing a good day in the garage couldn't fix. Pulling the plane outside he then went back inside to grab his tool box, looking at the plane he wondered as to what task he should complete first.

Maybe I'll start by fixing the dents first... he considered rummaging through his tool box. But then his attention was caught by a shadow suddenly being cascaded over him. His eyes darted up and he saw a (A/T) perched on the wing of the plane smiling.

"Hi there." she smiled.

"What are you doing here!?" he demanded taking a wobbly step back.

"Oh! So you did see me in Eggman's robot the other day." she giggled.

"Yes I saw you the other day but that still doesn't answer my question." he said sternly, regaining his posture.

Hopping down from the plane she kept that same smile on her face.

"My names (Y/N) the (A/T) and I came to join your team, gang, or whatever you call it."

"What?"

"You heard me."

Tails had to take a moment in order to fully comprehend what this random (A/T) had just said.

"W-what are you on about? Join the team? It isn't as easy as walking through a door!"

"Alright then what do I have to do? Some sort of test?"

"W-wait a second j-just slow down..."

"And here I was thinking your team leader was the fastest thing alive."

Tails gave a frustrated groan at her "So let me get this straight, you, a random stranger who I saw with our enemy, suddenly want to join our team?" 

"Yes! You finally get it!"

"No chance." Tails said turning his back on her starting to work on the Tornado.

"Oh come on!" she whined "Why wont you let me join?"

Tails tried is best to ignore her trying to carry on fixing his plane, but when (Y/N) started to climb on the wings and body like they were a climbing frame he finally snapped at her. 

"Why do you even want to join?"

She grinned in victory having got his attention.

"It's rather simple actually Your plane took quiet a beating but you still won, my guess is that your little gang is pretty strong, and I only help those who have assured victory."

She had no intention of choosing sides until she was sure who was going to win. The two fights she had witnessed over the last few days had told her which side would always win. 

(Bit ironic I wrote this sentence considering the beginning of Sonic Forces)  

"The whole world is essentially a war when you think about it, and a war suggests that both sides stand a chance of winning. I just like to be on the side that will win." she shrugged finishing her explanation.

She waited smugly for his answer but received a shock when all he said was.

"That is the worst reason ever to want to join the team." 

"Excuse me! My reasoning is perfectly valid!"

"But it isn't valid! So trust me when I say you've got no chance of joining this team, you might as well go join Eggman."

With that he turned his back on her again, but she was fully aware now that there was no chance of him acknowledging her again. But she had no intention of joining Eggman now.

Over the next week the (Y/N) seemed to make it her mission to becoming a royal pain in the backside for Tails. After every fight whether it be with Eggman or criminals she would hang around his workshop asking him constant questions.

"See? I told you you guys were the stronger side, you won again today?"

"Have you ever lost a battle? The one team I was on lost a battle once every week."

"Wow you lot are way better than the first team I joined, they argued all the time."

"You don't talk a lot do you?"

"I'm a strategist which is why Eggman was so eager for me to join him, so I figure out strategies, but you guys seem to make it up on the spot. That's impressive."

All the while he tried his very best to ignore her, doing well not to speak to her throughout the week, but come the seventh day...

"Have you ever tried Shawarma?"

"No! I have never tried Shawarma!"

"Really!? I ask you questions all week and that's the one you pay attention to!?" (Y/N) pouted.

Tails gave a heavy sigh leaning back in his chair, abandoning the circuit board on the desk.

"Why are you even here? I told you, you can't join the team."

"And why not? If you tell me why I can't join then I can go and improve my skills."

"There's nothing you can improve." he stood up and she nearly flinched at the length glare he was giving her "being on Team Sonic is more than just fighting the next battle, we stick together, we trust each other. But you don't have a scrap of loyalty, why should we trust someone who will leave us the instant someone stronger comes along?"

(Y/N) looked at him stunned.

"I've known Sonic since I was a kid and he's always been there for me and I know he's got my back because I've also got his. How do you expect to ever be truly on anyone's side when you have no concept of loyalty?"

(Y/N) was silent for a second stunned at his speech. But then she grinded her teeth.

"Well maybe I've 'got no loyalty' because I've never had anyone to be loyal to!"

It was Tails' turn to be surprised, but (Y/N) ignored his expression dashing out the garage.

"I get it! You don't want me here! I'll go join Eggman and you'll be sorry!"

Tails looked after her in the now silent workshop, not sure of how to feel. Should he feel glad that she was gone? Or stupid for giving Eggman an ally? Not only that he was considering whether to feel bad or not, by the sounds of it (Y/N) didn't have good friends like Sonic and the others. But she didn't have the right to come waltzing in and demand to be a part of the team.

But maybe if Tails hadn't of acted so cold towards her and given her a chance to prove she could be loyal things might have turned out differently. And things would have certainly been different if she hadn't kept pestering. It was hard to figure out who was right, and who was wrong. He gave a sigh sitting back in his chair.

"Why can't anything be simple...?"

~The next day~

Thankfully it was another quiet day, which Tails was taking the chance to think things over. He hadn't told anyone else about (Y/N)'s wanting to join the team thinking she would soon give up. Absent midedly flipping through his tablet he wondered what he should do.

"Hey buddy."

"Hey Sonic." Tails replied not looking up.

"Did you hear the bad news?" Sonic asked as Tails heard him rummaging in his fridge.

"What bad news?" he asked looking up and behind at him.

"Scourge has got a new member to his gang, a (A/T) apparently and she's really skilled. We'll have to be careful if and when we run into that lot. What's wrong? You've gone quiet all of a sudden."

"Oh! Uh..." Tails shook his head "N-nothing. But yeah, we'll have to keep our eyes open."

Later that day, when Tails knew there was next to know chance of an attack, was in the air as soon as possible. He didn't know what to feel last night but he knew what he was feeling now, guilt, in overwhelming amounts.

It's happened again. By that Tails was recalling his past lover Fiona, years ago she had betrayed the team and joined Scourge forgetting the right and just morals she used to live by. Although Tails could never locate himself in the reason she had left, he still blamed himself, despite Sonic's constant attempts to reassure him.

He was hoping to never be in this situation again, thinking he'd caused someone else to Scourge's sadistic team. But then he got a call.

"Tails? You there?"

It was Amy.

"Hey Amy, what's up?"

"Just thought I'd let you know it'd be best to stay away from Station Square, they just arrested the majority of Scourge's gang."

"What?"

"Yeah, I think it's literally only Scourge and Fiona now. But there's a lot of press over there right now so I thought I'd just give you a heads up."

"Th-thanks Amy, I'll see you later I guess."

"Okay, have fun with what ever you're doing."

She hung up and Tails had already turned the Tornado around headed back to the workshop. So that was it, (Y/N) had been arrested along with most of Scourge's gang. And although he didn't force her to make the choice of joining Scourge, he still felt guilty. Landing he headed back into the workshop, but jumped when he heard a quiet voice behind him.

"Hi there."

Darting around he jumped at the sight of (Y/N) stood in the door way.

"What are you-

"Well I may or may not have seen whether or not I wanted to join Scourge's gang but he was a total ass. You're way nicer, at least you're not shouting demands and insults every minute." she said casually shrugging "so when I heard they were going to team up with Eggman to take you guys down I may or may not have given the police a tip off so I could get half his gang arrested." 

Her casual explanation helped him put two and two together, whilst he could have jumped for joy that she hand't ended up like Fiona. 

"So what are you doing here?" he asked carefully.

She gave a shrug embarrassingly avoiding his gaze.

"I guess... I found someone to be loyal to."