Just a one shot, have too many current stories to take this further.
I do not own Destiny 1 or 2
I do not own A Certain Scientific Railgun
Story Start
At night at an unknown location at an unknown time.
"Just once, just once I would like to go into the Infinite Forrest without something going wrong. Just a few vex he said, no problem he said, just a simple job he said. I am so going to kick Osiris's ass as soon as I get back. But more importantly for now where the hell are we?" I ranted
"From what I can pick up this place is called Academy City, a place where almost everyone is a student. It was built for the sole purpose of studying and improving espers." said Casper
"What are espers?" I ask
"Basically they can do similar things that we can but with no connection to the light or Travellor, some can even do more remarkable stuff than we can and come in 6 levels. Fortunately they not nearly as strong as us with a level 3 esper roughly the same strength of a newborn guardian." answered Casper
"Please tell me that they isn't some sick plan to use these kids for some evil plan. Like an army of super espers of for someone to combine the power of all espers into one person to form a ultra esper?" I ask annoyance
Before Casper could answer there was massive explosion nearby, running towards the sound I arrive just in time to see a one-legged girl about to be crushed with a man leering menacingly nearby. Reacting quickly I blink towards her location.
Moments later
"Today's experiment is all done! I made quite the mess of things this time though. I wonder how they are going to clean this up? Well, I guess it doesn't matter. Oh I better head down to the nearest convenience store before it -." said the man before being interrupted as lightning streamed towards him before starring in shock a girl the exact copy of the previous girl charged towards him.
Elsewhere closeby
"Relax it will all be okay." I said soothingly to severely injured girl as I start to heal her "I've created a healing field around you, I've also numbed nerves so that you won't feel any pain. You're not going to die here trust me."
"Big sister." whimpered the girl
"That's your sister? Don't worry I'll keep her safe." I said with conviction as approached the fighting pair.
"What are you talking about? Absolute power? Invincibility? Is that why you're...Is that why you killed her? To get power?" questions the girl angrily as she flicks a coin with unbelievable force.
The next moments would forever be etched in the mind of one Mikoto Misaka, her railgun technique, the one that has always worked before...failed. And in almost slow motion the very coin that she had flipped bounced back...right at her face.
Then out of nowhere, a man was in front of her backhanding the coin away.
"Who are you?" question the man
"I'm the guy who you pissed of. Hey girl you should get out of her, its not safe here." I informed the girl
"I can't...I can't he killed..." whispered the girl racked with guilt
"Your sister's alive, I've put her over there in a healing circle. She'll make it put she definitely needs her big sister." I said while pointing behind me
"She's alive!" said the girl in shock
"Yes, I got there just in time to save her." I told her
"So the other one's still alive? I'll have to fix that after I kill you two." said the man arrogantly
"Yeah that not going to happen." I said firmly
"Oh? And how are you going to do that? I am the strongest level five esper, you are.." started the man before being interrupted by a short chaos lance to the chest blasting him back.
"That, that is what I am going to do you jackass. Now hurry up and go to your sister and while your at it grab her leg while your at it, I should be able to reattach if it's not too damaged." I said firmly
"Right!" she replied as she ran off
"Wow that was pretty impressive! Who knew that there was an esper as strong as you." goaded the man as stumbles to his feet
"Yeah let me burst your bubble right now, that 'impressive' attack was the equivalent of me taking a piss. The fact that you mistake it for a powerful attack just says how weak you are." I said insultingly
"How dare you! I am the best of Academy City! I can handle everything you can throw at me! So come at me so I can become level six!" shouted the man deranged
"...Ok have it your way." I said calmly as the girl runs of towards her sister
It wasn't long until she had reached her sister, a field of glowing white energy around her.
"Your alive thank goodness...I'm sorry, I'm so sorry." she whispered barely noticing the purple explosion behind her
Before too long she was joined by the mystery man
"So I'm guessing you and/or your sister are clones?" the man asks
Turning around in shock the girl asks "How did you know?"
"Well it's that or your parents never heard of birth control." he says while pointing behind her
Turning around all she can do is gap at the literal army of herself in front of her
"Where is Accelerator?" asked one of the clones
"The testing must continue." said another
"The experiment cannot fail." said a third
"Big Sister should not be here." said a fourth
"What?...You mean you're going along with this willingly? Why, why would you do such a thing?" asked the girl
"You think they have a choice, if I'm correct I'd say that they were never once asked what they wanted to do and were 'programed' in some way to make sure they follow orders and that any who discided not to follow orders were 'removed' from the situation." I said as I kneeled down to reattach the girls leg
"Our lives have no value...the only thing we can do to be of value is to die so that Accelerator can reach level six." said another clone
"Besides when we die everything we have learnt is transferred to the collective so nothing is lost."
"So please direct us to him so that we can finish testing for tonight."
"Okay well some of him is there, a bit more over there and some way over there." I said pointing in a few random locations
"Accelerator is dead? But dying to him was the meaning of our lives?" asked another clone and though her voice was almost emotionless I could detect that this girl was absolutely terrified or was it devastated?
"You do what everyone else does...you find your own purpose, your own meaning of life. Your purpose was never to die for some sickening experiment thats just what you were told, thats the only thing you were told wasn't it...that your only purpose was to die so some punk could eventually level up? Also am I right in thinking that the transferration that you were talking about doesn't include any emotions, any feelings assosiated to them?" I ask "Like what the sun feels like? Or the beauty of a sunset?"
"No, today I have learnt so many new things, I have learnt what it is like to receive a gift from big sister, I have learnt what it is like to feel the sun on my face, I have tasted the marvels of ice-cream. I do not want to die after just learning what is like to live says Mikoto fearful she will die and not experience any new memories."
"Well if I have anything to do with it you're not dying today and all of you will have nice long lives." I said