y/n pov
i woke up and saw aunt nemuri holding me
y/n: whats going on?
nemuri: morning y/n~
y/n: where are we
all might: we're at the mall y/n
y/n: oh great
i jumped out nemuri's arms and walked beside dad
aizawa: wow y/n, your even taller
y/n: huh?
i was, i'm half dad's height
y/n: i guess i am
we walked into a shop, dad gave me some money and asked me to get a couch since aizawa broke our old one by throwing mic into it
store clerk: hey little guy, what ya looking for?
y/n: i need a curved 16ft couch
store clerk: oh do you have someone to help you with that?
y/n: I've got it
store clerk: well follow me
i got the couch from the clerk and walked out the store and met up with dad and the others
all might: well done y/n
y/n: thanks
we walked home, once we got home i got changed into my training clothes and got taken to grand torino's place to train
time skip
5 years had passed, i had mastered one for all, grown to 7ft and gotten my hero costume
all might: you look amazing son!
y/n: thanks dad
out of nowhere we got a phone call, dad picked it up and i instantly saw his face turn into one of distress
y/n: what wrong?
all might: it's all for one, i need to go!
y/n: we need to go
all might: no y/n you stay here!
y/n: dad you know what he did to nana, i don't want that to happen to you, so i'm coming with you
all might: no-
i glared at him
all might:okay, but stay with grand torino and only move in if needed!
i nodded and we blasted of into the sky, we got into the next district and saw an air blast heading straight for us
all might: dodge!
we split, when we landed we saw all for one grinning at us
all for one: all might, grand torino, and sweet little y/n
y/n: don't call me that
all might: for your crimes against the people of the world and the murder of my predecessor, i will take you down, and lock you away for the rest of your life!!
all for one: come on then, symbol of peace!
dad dashed at him, they collided fists creating a huge burst of air knocking me and torino back
y/n: shit! torino move in!
grand torino: y/n no!
i rushed in as dad got launched backwards, i stopped him and grabbed his hand
y/n: launch me!
he spun me around and launched me at all for one, i collided my fist with his face breaking his nose and jaw knocking him back, i dashed forward with dad and we both punched him in his chest breaking his sternum, he instantly turned at us and blasted us with fire, we blocked it as grand torino dashed at all for one and kicked him jaw breaking it worse
y/n: dad now- ahh!!
i looked down and saw a metal rod lodged in my chest
all might: y/n!
y/n: no! finish him!
he looked shocked but still dashed at all for one, he reeled his fist back trying to end all for one, but instead, all for one grabbed his side and crushed it
all might: AHHHHHH!!!
grand torino: toshinori!!
y/n: dad no!!!
i felt a strange feeling like a burst of energy, i dashed forwards and grabbed dad and torino getting them away from all for one
y/n: sir! treat dad! i'll end all for one!
torino: no!
all might: y/n!
i dashed forward and saw all for one charge an air blast, i pushed through the blast and grabbed his hand crushing it, i pushed his arm to the side and grabbed his face crushing his jaw
y/n: you bastard!
all for one: stupid child!!!
we both punched each other at the same creating another huge burst of energy, dad and torino looked on in worry as multiple explosions occurred, i grabbed his arm and snapped it, he punched me away with his other fist, dad managed to get up and dashed at all for one
all might: all for one!!
all for one: all might!! huh?!
i grabbed his other arms and kicked his leg knocking his back, dad reeled his fist back and collided it with all for ones face, i also connected my fist with his face with my full adrenaline pushing him down, me and dad let out a war cry and crushed all for ones head creating a huge blood splatter and killing all for one, we were both panting when i looked at all for ones corpse
y/n: w-what? what? did? i? do?
i began to tear up as dad looked at me
all might: son
i got up with my head down and my eyes distant
all might: y/n...
he got up as well and we walked back to grand torino
grand torino: what happened?
i walked past him and towards the police, i saw tsukauchi
tsukauchi: y/n? what happened-?
he gasped as he saw the distant look in my eyes, he saw dad walk behind me with a similar look, before we both bled out we got taken into an ambulance
all might: y/n, i'm sorry-
y/n: don't, just don't
i couldn't believe it, i was only ten years old, and i just killed the symbol of terror and death in japan
y/n: fuck
time skip
i got out of the hospital and got taken home by tsukauchi, he told me not to speak about what happened, once i got home i went up to my room and cried my eyes out, i heard the main door open and dads voice along with a few others filled the hallways, i couldn't understand what they said as i was still crying, i heard my bedroom door creak open, i looked at it and saw dad stood there
all might: y/n...
he walked up and sat down next to me and petted my head
all might: its okay y/n, i know you didn't want to do that, neither did i,but you made the most difficult decision a hero has to make in their career, and for that i'm proud of you son, come here
he gave me a hug as he stroked my hair
all might: its okay to cry
i began sobbing as i clutched at the back of his shirt
all might: its okay son, its okay
y/n: t-thank you, dad
time skip
i was sat on the couch watching TV when dad walked in with aizawa, mic, nemuri and principle nezu
y/n: whats up
all might: son, we have to ask you a question
nezu: would you like to attend UA high when you become of age?
y/n: of course