Hello lovely reader. This the very first FanFiction that I am posting, a spinoff of the Toaru series and what it would look like if my OC was in it. This is meant to be similar to what Railgun is compared to Index, though the first arc takes place during the poltergeist arc of Railgun, since that is where my OC was meant to be introduced. Well, enough explaining, lets get started. Hope you have a fun time reading.

Prologue: The Strongest Gemstone

Academy City. Located within a walled enclave in the Tokyo Metropolitan Employment Area, it is the most scientifically advanced city in the world, with 2.3 million civilians of which 80% are students. The technology in the city is 30 years ahead of the rest of the world, having weaponry far more advanced than any military out there, security robots and powered suits are everywhere, and this is the only city in the world that can produce espers.

"What is an esper?" you might ask. Espers are human beings that have undergone the Power Curriculum Program of the city and have their minds separated from standard reality to create a Personal Reality. They radiate an AIM Diffusion Field which brings their Personal Realities into the standard reality, causing them to have supernatural abilities, which are ranked 0 through 5. With Level 0s having almost to no power whatsoever and Level 5s being strong enough to fight an army alone, of which only 7 are known to exist. There's also a theorized Level 6 which is yet to be seen.

"Okay Gunha, let's try your voice amplification next."

"Alright Kinuhata-kun. You might want to block ears, cause this one's coming right out of my guts!"

Looking at the monitor was a boy named Kinuhata Kaiteki, a 17-year-old third-year high school student with short brown messy hair and blue eyes wearing a white V-neck with a short-sleeved open black jacked over it. Kaiteki is currently at the AIM Analytic Research Center, researching a boy about his age on the other side of the glass. The boy had somewhat windswept black hair and a headband on his forehead wearing a Rising Sun shirt and wearing his uniform like a make-shift cape, Sogiita Gunha, the #7 Level 5 esper in Academy City and the strongest Gemstone. Kaiteki specializes in AIM Diffusion Fields in his own free time, and he researches Gunha because of his unexplainable ability. And since it's summer break, there's no better time then now.

"I don't think that's how screaming works, Gunha. Besides, the room you're in is soundproof, and I hear you through a mic which I can turn off."

"Okay, whenever you're ready!" says Gunha.

"Go for it!" says Kaiteki in a slight impatience.

Gunha deeply inhales and …

"AAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHH!"

He screamed louder than a speaker at concert hall. It seems so loud that a Powered Suit in that same room got blown back towards the wall.

"ALRIGHT GUNHA, THAT'S ENOUGH!" Kaiteki as loud as he could to reach Gunha.

"AAAAAAAAAAAaaaaahhh. So how was that?" Gunha asked.

"WHAT DID YOU SAY?!" screamed Kaiteki in a sarcastic way.

"I SAID-! Oh wait, I get it."

Kaiteki rolled with his eyes.

"I got the results. Now we'll try… let's see… let's try your signature Attack Crash, shall we?" says Kaiteki.

"Okay."

With a few presses on the buttons, Kaiteki activates the Powered Suits that are left standing. The Powered Suits activate and move towards Gunha. Gunha stomps his right feet on the ground, closes his eyes and deeply breaths out. He then takes a karate-like stance, widely opens his eyes and screams: "Amazing Punch!". He then throws his right fist and an explosion occurred. They were not even ten meters away, but the Powered Suits were immediately destroyed.

As Kaiteki watched the monitor he seems to notice something he didn't notice before.

"Oh wow! Gunha, you need to see this!"

Kaiteki opened the door to let Gunha out.

"What is it, Kinuhata-kun?" asked Gunha.

"Look." says Kaiteki.

Gunha looked at the screen and Kaiteki showed his results. On the screen were two different camera footages playing. One that recorded regularly and the other recorded AIM Diffusion Fields.

Kaiteki played the recording of the tests and explained to Gunha what he sees.

"To start off, do you remember why I wanted to research you?" asks Kaiteki.

"It's because even Academy City cannot explain my ability, right?"

"Precisely. It seems like your AIM Diffusion Fields is bending and twisting in an unstable way, even when you're not using your ability. However, when you do use your ability, it stabilizes for a short time, but it somehow behaves differently depending on the power. Look here at your Attack Crash."

Kaiteki pointed his finger towards the two screens whose footage moved in sync with each other and continues to explain.

"It seems as though your AIM creates "something" in front of your fist and the moment you release that "energy" by punching, it creates an explosion that can reach more than 10 meters away."

"Maybe I create an unstable wall of psychokinesis and destroy it with my fist as stimulus, causing an explosive aftereffect." says Gunha.

"That's not how physics work. But to get back to the point, when using your voice amplification, your AIM Diffusion Field acts completely different."

Kaiteki, once again, points his finger at the screens that's now playing the voice amplification clip and explains what he sees.

"When you use your voice amplification, your AIM is more focused at your mouth and throat and seems to strengthen your scream as a result."

Gunha grabs his own chin and thinks.

"Maybe my AIM Diffusion Field acts as some kind of megaphone or something." Gunha tries to explain.

Now Kaiteki grabs his chin. "That may be a possibility, but that still doesn't explain how your Attack Crash works. No wonder that Academy City isn't able to understand it, it just has so many effects that we can't classify it. But I do have a rough theory now, maybe we can't classify it because it isn't just one ability. Gunha," Kaiteki turned his chair around 90° with his arm on his backrest looking directly at Gunha. "I think you're a Dual Skill."

"That's ridiculous. According to scientific research on espers in Academy City, espers are unable to have more than one ability."

The two boys turned around and behind them appeared a scientist in about his mid-forty's with a guard behind him. Kaiteki stood up and walks towards the scientist.

"But that's my point. Gemstones have a much larger AIM Diffusion Field than the ones we create here in Academy City, and most of them have abilities that are not related by science. Besides, there are only about 50 of them around the world, there isn't enough evidence to conclude that they can't."

"That doesn't matter, our espers are the same and work the same. If our espers can't have more than one power at a time, than Gemstones can't either. It's because the brain cannot handle such immense calculations." The scientist shoves his glasses up his face. "Anyway, your time's up. You'll have to come back another day."

"Alright. I'll shut this down, then we're gone." answers Kaiteki.

"Excellent."

After they finish shutting everything down, Gunha and Kaiteki walk outside and talk further about their research and the summer break.

"You really think I have the guts to be a Dual Skill? I mean, it's just like that scientist says, our brains can't handle it." asks Gunha.

"It is just a theory for now, and I don't have a better way describe it. Besides, what he said isn't entirely true. Remember that there is an esper that might control Personal Realities once reaching Level 5." answered Kaiteki.

"Right… Wait… No… Crap, I forgot."

Kaiteki sighed. "Well, no harm in repeating myself. I've heard that there is a certain Level 4 esper who can track AIM Diffusion Fields. It is said that if that person becomes a Level 5, then she can manipulate Personal Realities and is able to give someone Dual Skill."

"That's a lot of guts. Anyway, a bit off topic but would you like to go to the firework display tonight? Or don't you have the guts for it?" asks Gunha.

Kaiteki seems to be a bit surprised by Gunha's offer.

"Seriously?! You, a Level 5, are asking me?! We're not even friends!"

"Hey, I know we only know each other from your research and from school, but it's no reason to not invite you. So, up for it?"

Kaiteki is someone who isn't really that popular and answers a bit awkward.

"S-sure."

"Great, then we'll see each other tonight. Well, I still need to buy some groceries. See ya later!" says Gunha as he leaves.

"See ya".

So, what did you think of the prologue? Was it a good start? Was it a bad start? Did I make any mistakes? Let me know what you think, but please keep it polite. Anyway, I hope you enjoyed it nonetheless.