Hey Kid -(bnha &fairytail crossover)

Nothing is for free

'16,17,18,19.'
The detective counted.
'Other than the boy with green hair and the tiny girl, everyone seems fine.'
'Mister, what about Aizawa-sensei?' Tsu ribbited.
'Ah, right. He is your teacher, so you would want to know. His elbow was badly messed up and he has a facial fracture. His orbital floor has been broken into a few pieces, so the doctors are unsure if he'll ever be able to see again.' The detective started.

Being met with an uncomfortable silence, the detective added, 'The doctors also say it could have been much worse.'

Mina jumped up. 'What happened to Thirteen?'

Uraraka butted in. 'Deku! Is Midoryia alright?'

Todoroki and Iida nodded by her side, the trio genuinely worried for their bone-breaking friend.

Momo raised her hand. 'Detective, is YN alright? From what I saw, she took on the monster that All Might was exchanging blows with.'

The entire class perked up.

'LN did fight the Nomu.' Todoroki confirmed.

'Ribbit. YN made me doubt that the Nomu was ment to defeat All Might.' Tsu commented, finger on her chin.

'Yeah! LN was so cool! But seriously though, All Might didn't defeat it as fast as YN did, right?' Kirishima punched his palm. 'So manly!'

The detective coughed, regaining everyone's attention. 'Thirteen, All Might, Midoryia and LN have been placed into Recovery Girl's care. She will be enough to heal them all. Although, from what I heard, LN seems to be just sleeping.'

The students started chattering again.

'I didn't see the fight, but why did LN have to step in? All Might could have won, right?' Kaminari questioned, drinking from a portable charger.

'She had some fucking power up- twice!' Bakugou yelled, fuming.
—————
Back at the infirmary, you were covered in a thin sheet of sweat. You were trembling, hot, cold, freezing, burning. Purple bags could be seen under your eyes, and your heart was beating irregularly. Recovery Girl looked at you worriedly, before your entire class burst in. Luckily All Might scurried away in time.
'Is LN alright?' Mina yelled.
Iida chopped worriedly behind her.
'Yeah! Bakugou stop struggling!' Kirishima yelled, holding a Bakugou that was screaming profanities and thrashing around.
Recovery girl looked at them, not speaking.
Everyone stopped, seeing you behind her short figure. Even Bakugou.
You looked terrible. Your breaths came out in sharp short gasps, your face paler than normal.
'What the fuck is wrong with her?'
'I don't know. Nothing is working, the hospital said there was nothing wrong with her, she's not in a coma or anything.' The short woman informed them of what the professionals said.
Bakugou grit his teeth. 'What the FUCK? That's their job!' He lashes out.
Just after that second he finished shouting, your breaths became louder, sharper, more ragged. In a flash, the entirety of the class dashed to your side. Forget broken bones and All Might, you had an UNKNOWN sickness. You looked horrible.
The end of lunch bell rung, and everyone left.
'Hey, Bakugou, you seem pretty worried 'bout YN, you like her or something?' Denki elbowed the mentioned explosive blonde.
Bakugou punched the lightning bolt in the face, blasting him away.
'BAKUGOU!' The class yelled.
He ignored them.
'What the fuck dunce face? What the fuck? She freaking lives with me why-'
Kaminari stood up again, not getting the picture, being too dumb to understand the time to stop. 
"She lives with you, eh?"

'KAMINARI!' The class shouted.
'WHAT THE FUCK SHE'S LIKE A SISTER TO ME WHAT THE HELL IS WRONG WITH YOU!' Bakugou stomped off, embarrassed that he told everyone that he appreciated you.
—————
Later, in the infirmary, Aizawa and All Might and Recovery Girl crowded around your sickbed, worried. All Might was in his small form, Midoriya, sleeping.
They didn't know what this sickness was-
—————but back home, every mage knows.

Magic Deficiency Disease
(魔力欠乏症 Maryoku Ketsubōshō)
is a term that refers to when a Mage is rapidly deprived of their Ethernano, causing them contract an illness.

Description:

Magic Deficiency Disease causes the recipient to fall ill from the rapid loss of their Magic Power, which can either be from using a massive amount all at once or having it drained from another person. In dire cases, the disease can cause death if deprived enough of their Ethernano. Cures for this disease include potions and medicines to replenish Magic, which you didn't have right now.
———————
But the teachers didn't know that. And to their surprise, you started flickering, as if you were merely a projection.
.
Back at Fairy Tail, Levy wiped the sweat off her forehead.
' I'm not sure what happened, but YN's etherious book is linked to her and think I can bring her back!'
They had opened up your book, that they kept in the basement. Somehow it was indestructible, and they didn't want to turn you into a demon, wherever you were. So Levy opened it herself and and started editing furiously. Natsu and Gray were on her sides, warming her up and cooling her down from the after affects of the consequences of opening the book.
'Guys she might be back-!' Levy said, falling onto the equally tired Lucy.
Your form flickered, and you stood up.
'YN!!' The guild shouted, before parting ways for Erza. She punched you in the stomach. 'Don't leave is ever -!'
Her fist went right through you, your form flickering again, rippling as if she threw a rock in water.

Your body wasn't really there.
'T-Thought projection?!' Erza stammered. 'What are you playing at, YN!'
You looked at her, eyes watering. How long was it since you've saw her? But you had to make things clear.
'Not quite, this thought projection is allowing me to gather up etherano, because well, I think I had magic deficiency? Anyways, I think the reason I can't come back is because I have something to solve first, in this other world.' You explained, not really sure yourself.
'You are not doing anything of that sort. We will find a way to get you back and you will stay.' Erza slammed her sword on the ground.
'Erza- I-I- You-!' You fumbled with your words under the glared of the powerful mage before you.
Looking down, you blurted out your words.
'I know there's something wrong with that world, something really bad's gonna happen, and -I-I, I can't leave my friends and "family" alone! That's the Fairy Tail way, am I plan to keep to it, even in another world!'
Your fists were clenched, and you squeezed your eyes shut before opening them again. Looking up at Erza, you clenched your fist punching it up to the roof, before flicking your index and thumb out.
'Don't worry about me, alright! I'm a Fairy Tail mage!'
'YEAH!' The guild shouted, joining in.
Erza smiled, gaze relaxing. She's grown up.
Your body began to flicker, disappearing into golden dust.
The book! Levy opened the E.(first initial).(last initial)! That's why I turned into a demon! Ohhhh!
———————
You were looking much better suddenly, peacefully sleeping now. You stirred, the teachers looked at you as you sat up, wait but All Might was still tiny!
'WHY THE FUCK ALL MIGHT IS TINY?!'
'Uhhh..'
'You know, if you trust me with your secret, I would trust you with mine.' You waved your hand dismissively. You didn't think much about it, the pain killers numbing your already kinda-dumb-brain.
All Might thought for a bit and nodded, as Aizawa and Recovery Girl left the room.
-——–
Next chapter, Secret for secret!
But before that there's a vote I want you guys to do on the next page!