Manga Spoilers about Shigaraki's backstory (gonna be in S5 I think):
"Y/n!" Tenko yelled, laughter in his tone as he ran into the living room, his little feet thumping against the hardwood. "Y/n, come on! You said you were gonna play heroes with me,"
The boy's black hair crowded his face, the light from the windows casting pretty shadows as he searched every corner of the house for his little sister.
Since he was so young he could barely speak, Tenko adored heroes. He looked up to them, thought they were the coolest, most amazing people on the planet. For birthdays, he wanted dolls of his favorites. When he played outside, he pretended he could fly or had super strength or was beating up imaginary villains.
Thing is, Tenko's father wasn't all too fond of heroes. He made that clear to his wife, in-laws, and children too.
Kotaro Shimura was his name: the man who wanted nothing but a happy family.
His mother was Nana Shimura. And she left him when he was all too young. Because she had to go off and save other people rather than care for her son. The betrayal he felt from that experience was too much to bear.
So every-time Kotaro caught his son playing like that, a pain struck his heart he couldn't quite explain. That was his son, his family. Therefore, he couldn't idolize something as selfish as a "hero".
The thought alone made Kotaro boil with rage and sadness and too many emotions he couldn't handle. So whenever Tenko went against his father's wishes, he suffered the consequences.
Whether it was shoving him in a closet even though he was afraid of the dark. Or slapping him across the face. Or locking him outside till the night became so cold he had to hide in a little tool shed...
Kotaro Shimura wanted nothing but a happy family. So much so that he was willing to abuse his own child if only to protect his values.
But Tenko never learned his lesson. He still wanted to be a hero. He lived out those hard days never letting go of his dream.
His mom, his grandparents, his older sister even- they all made excuses for his father. Never stopped him. Never truly defended him aside from the occasional comment he was being 'too tough.
Life felt pretty lonely because of that. It's hard not to feel alienated when those who are meant to love and protect you ignore the fresh wounds inflicted both to body and mind.
On top of that, no one at school wanted to play with him since he was so odd looking. They called his allergies, his scratching disgusting or weird. They'd push him off the swings. Bully him for being smaller than the others.
Life was very lonely for the boy who wanted nothing but to be a hero.
That all changed though...
When he met you...
Tenko still remembered the day his mom and dad came home from the hospital with something in their arms. He jumped up and down, too curious for his own good, his mom kneeling to show him his new little sister.
He stared down with wide eyes, wondrous at the little baby wrapped up in a blanket making dreamy noises as she slept in her mom's arms.
She was so tiny and new to the world.
Hesitantly, Tenko reached out, felt the soft skin of her arm. The baby fussed slightly, scaring him but-
When she grabbed his thumb and woke up, her gaze reached his. And for the first time, she met her big brother, Tenko's eyes shinning with so much joy it even brought a smile to his father's face.
Ever since then, Tenko sat by her crib, took his naps on the floor of her room, helped his mom feed her till she could feed herself. He talked to her even if she couldn't understand what he was saying. He asked her questions about her favorite colors and her favorite movies when she was too young to even answer.
Some people, including his family, thought it was a little strange he was so attached. Someone who he couldn't communicate with till she was older.
But they didn't understand.
Watching her grow. That smile on her face. The little fits of laughter she let loose when he was near, it just...
A baby doesn't care if you have scars on your face or if your dreams are a little too far from reach. And when she looked at him like he was the world, Tenko didn't feel so alone anymore.
It made all the darker moments, all the other people in his life who's smiles were fake and whose laughter was forced fade away...
"Y/n, it's my turn to be sidekick this time!" Tenko yelled again, so glad to be home from school and able to see her.
Of course just as he reached the hallway into the living room, he crossed his older sister Hana.
"Quit yelling Tenko," Hana said, annoyed.
Hana wasn't mean. She never bullied Tenko, she just didn't understand why he held onto such ideas when it only got him in trouble. And though she loved her little sister, unlike Tenko, she didn't want to be around a toddler all the time.
"She's only three," Hana went on, running up the stairs and to her room, "She doesn't wanna play your stupid games,"
Tenko rolled his eyes at that, plopped his backpack down on the ground by the couch, happy that his other sister was sitting there waiting for him.
She didn't understand that much yet, but as soon as she caught sight of Tenko, her eyes shut, that big smile he loved so much curving her lips as she rocked her legs back and forth. Her hair was all messy because she hated brushing it and her sweater was too big, probably Hana who dressed her up again.
"Hi Y/n!" The boy cheered, returning her expression as he trotted up right in front of her, pitter pattering. "Sorry Hana won't play with us. She says it's cause dad doesn't like heroes,"
"I wanna play," She said, little voiced, still learning how to speak in full sentences.
"Yay!" Tenko cheered, his feet tippy tapping in excitement as he reached out for her hand to help her off the couch. "Let's go outside then!"
Getting ahead of himself, the boy started running to the door before realizing his little sister wasn't following.
"Y/n?" He called, looking back over his shoulder. "What's wrong?"
Rubbing her eyes and stumbling a bit, she looked slightly disoriented. Almost like something had knocked the wind out of her.
Tenko put his arms out to catch her if she fell. Since she was still so little and clumsy it was quite the common thing that she'd knock into things or fall over. Although she never cried much, never complained. She even chuckled whenever Tenko would freak out thinking she'd bruised or cut herself.
Still, this seemed a little different, like something wasn't right.
Making a little pained humming sound, the girl rubbed at her eyes again, harder this time.
"It's hot," She mumbled, almost falling backwards into the coffee table.
Trying not to panic over it, Tenko nodded, catching her by the shoulders and keeping her upright.
"Here," He said, reaching for the hem of her sweater. "I'll take this off for you,"
"Thank you," Her words were more broken now, the way she spoke when she was sleepy.
Once Tenko got her sweater off over her head though, he almost fell backwards. A sudden light above his sister's head shining so bright the little boy nearly jumped backwards, spooked out of his skin.
"What is it?" She asked, eyes still half lidded, her energy suddenly drained for some reason.
"You're-" Tenko stuttered, the sweater grasped in his hands. The mass of light around her was so eye-catching, but at the same time, confused him so much. "You're glowing, Y/n,"
***
Tenko fumbled with his fingers sitting in the chair at the doctor's office.
After seeing the glowing mass of light going in and out slowly like fireflies around his sister's head, his mom came rushing in.
She asked if her daughter was okay, afraid to pick her up for some reason, but still worried as much as any mother would be if they saw their child surrounded by random glowing shapes.
Tenko's little sister just nodded a few times, but she was so tired she nearly fell over again.
He was so worried he couldn't even speak for a while. When his father picked her up, brought her to the car, strapped her to her seat, Tenko climbed in too without even asking.
He didn't say a word, his mom telling him he should go back inside. But he didn't listen. Just threatened to cry and throw a fit if he didn't get to go to the doctor too.
Now, he sat behind his mom and dad's chairs who were facing the physician. His sister didn't even cry when she got blood drawn, just hugged her mom, confused as to why everyone was making such a fuss. Honestly, she just looked eager for a nap.
Before the physician even got started, Tenko felt a panicky sort of feeling crawl through his veins- couldn't help but itch with the anxiety at his neck and eyes.
"So this is her quirk? I didn't know it would develop so early." His father said to the doctor, petting his daughter's head.
"We believe so, yes." The doctor informed him. Tenko looked up to see a man wearing round glasses, an odd sort of lab coat around his chubby body. He was quite short too. Looked more like a movie villain than a doctor. "The glowing was just a mass of chemical reactions her quirk was attempting to create to deal with the heat."
A quirk?
Not even Tenko had a quirk yet.
"Little Y/n- your body just wanted to protect you from the summer, understand?" The doctor said, but she wasn't really listening, didn't understand. Instead, rather bored, she turned around in her mom's lap so she could see Tenko over her shoulder.
"So, does this mean, y/n's quirk is like chemistry?" His mother asked, patting her child's back as she tried to wiggle closer to her brother to see him better.
He wasn't smiling right now. Why not?
She loved it when he smiled.
The girl tried to reach out her hand much like Tenko often did for her. When the boy looked up, seeing her reaching for him, it made his face droop.
"Hah," the doctor laughed at his mother's question. "I guess you could say that, yes, but for now, we don't quite understand how it works. And it could potentially be dangerous without control."
Instinctively, Tenko's mother pushed her daughter away slightly, picked her up from under the arms like a puppy and scooted her further back on her lap out of fear.
It was so sudden Tenko didn't get a chance to return her gesture.
"Don't worry ma'am," The doctor said, leaning closer, as if curious about a child he could very much treat like a science experiment. "We aren't sure of the ramifications this could have on her body or others, so for now, it would be safer to keep her separated."
"Separated? Even from us?" His father asked, concerned too.
After all, he had other children. Other children to keep safe at home.
"This won't be permanent. Just avoid physical contact." The doctor said, "We only want to get a sense for how this quirk functions. We've never really seen anything like it before. We're going to need to do some tests. Electroshock among others to see how she responds to it,"
"Won't that hurt her!?" Tenko's mother objected.The girl in her lap blinked, her chubby baby cheeks pouting as she tried to hold her mom who just kept pushing her back, keeping her at bay.
"It may, but she's young enough that she probably won't remember the pain anyway. What's important is keeping your distance from a power like hers. It's young too and it'll only get stronger. But with time, little Y/n, I'm sure this could end up being something wonderful."
The doctor smiled down at the girl oddly, patting her head as her mother set her down on the ground.
"Who knows?" He went on, packing up the x-rays. "You may even make a hell of a pro hero one day with a power like this."
Despite how oddly her family was acting, the little girl beamed at those words.
A hero? Just like Tenko?
After blinking up at the doctor in awe for a few seconds, the girl turned around, began smiling and laughing through her teeth with excitement. She looked at Tenko, jumping up and down much like he did when he was excited too.
Tenko was still in his chair. And though he was so happy for his little sister to have a quirk, unlike her, he very much understood what was about to happen. And it hurt like hell to know that pain was in her future.
But so she would feel that everything would be alright- so she could have a hope that her happiness would last- he smiled for her too... So she would believe that everything would be okay.
"Don't say things like that," His father bit at the doctor, starting to follow his wife out of the room. "Follow us, Y/n,"
The girl nodded with a little hum, excited to finally go home after such an odd day at the doctor's.
However, when she reached for her mom or her dad's hand, neither of them took it. They just... walked away... like they were afraid to touch her at all.
The girl's face fell, her body paralyzed at the doorway.
She didn't understand. Just stood there for a second wondering why neither of her parents were there anymore. Tucking her hands back close to her chest, she felt her lower lip start to shake, her eyes turn glossy.
She was three years old. Mom and dad had always been there. Even grandma and grandpa too. Someone was always there to hold her hand, to pick her up, why did they go away? Why was it so cold all the sudden?
Just as she was about to start crying then, the girl heard the tippy tapping sounds of little shoes against the tile floor of the doctor's office.
"Come on, Y/n," Tenko said, running up to his little sister and interlacing his fingers with hers. "We still have to go play heroes at home, remember? Also, mom said we can get ice cream, you love ice cream!"
The joy in her brother's voice seemed so real, the warmth of his hold even more so. And so suddenly, even at three years old, the little girl could understand what real love was too.
***
When your eyes opened, you were real again. In someone's arms, your limp body carried as you re-awakened from the world Eri sent you to.
"Wait!" A little voice yelled, the faint image of Eri being taken away blurring in and out along with the image of the hideout. "I didn't finish, she doesn't remember everything, yet!"
Sounds of crumbling concrete and yelling filled your ears in a muffled mess. The child protested, whoever was tugging her away from you under attack.
You were so delirious. You couldn't tell whether you were still watching two siblings holding hands as they walked out a doctor's office or you were waking up to some kind of battle. Both realities flashed in and out, making you squint and groan as you once again felt the physicality of your surroundings.
"Strata!" The person holding you yelled, their voice so familiar. They shook you once, carrying you with an arm around your shoulders, the other cradling your legs. "Y/n, wake up! Oh my god, you're bleeding,"
They were so panicked, their attention on you then on kicking off the ground to avoid possible attacks.
"Deku! Mirio! Get them both out of here!"
Nighteye? You thought, knowing that voice was all too familiar.
But your mind was still heavy with feelings you couldn't quite understand.
Your parents' faces. They finally gave image in your mind. Their clothes, their hair. The feel of their skin. Their gentle coaxings as you slept in your old room. Even their voices as they uttered your name.
Your sister. Only a few years older than you, with black hair that shined as pretty as her eyes. She had a temper, an innate selfish tick, yet she was always kind to you. You remembered the times she poked your nose and laughed as you got confused, so young. Her laughter resonated. A beautiful girl who you didn't even know shutting her eyes in your memory.
...Your brother. Tenko. His little hand tucking yours away when no one else would hold it. His smile so heartwarming it cracked your heart in two. A boy whose face had yet to be tarnished with fear and death and abandonment-
"Tenko," You breathed, a single tear streaming down your face as you reached for him the way you once did in your mother's arms rather than in someone else's now.
"Y/n!? Are you okay!?"
Deku.
When your vision finally returned and you heaved in a breath, you were able to catch the green hair framing the crying hero's face. He held you against his chest, peering down as his glossy eyes welled.
He was bleeding too, his costume torn around his arm as he panted from whatever fight he'd undergone.
"I thought you were gone for a second," Deku cried, hugging you to him as more sounds of the building collapsing made him jump backwards. "We have to get you out of here-"
"Eri," You said, voice hoarse, still trying to readjust. "Where's Eri-"
"Mirio has her, it's okay," Deku said, ducking and shielding your body with his as more debris fell from the collapsing underground base.
Overhaul's quirk. Decay and Restore. Was he... Was he using the entire building to keep anyone from escaping? Or had his earlier attempts to manipulate his surroundings using Mimic evolved?
"Where are the pros-" You stopped, coughing a fit as Deku set you back on your feet, still keeping his hands on your shoulders, protectively.
His gaze was frantic, searching for a means of escape as his power surged inside him, lighting his skin with green flecks, causing his muscles to bulge, ready for action.
He'd been through so much in only the past hour or so, getting separated from his teachers, having to fight multiple thugs at once, straining his body to its limit.
He was himself, Izuku Midoriya, but when you woke, if only for a moment... As peering down at you that way, so worried for your wellbeing, you swore you saw someone else wishing to keep you safe behind his eyes.
"Deku!" You yelled, pulling him backwards as shards of concrete started to poke out the ground, a creature that could only be Overhaul at the center of the room planting his hands to the earth.
He wasn't just using his quirk to make the ceilings unsteady as his minions had, he was using it to kill whoever got in his way.
"Children!" Nighteye yelled, the pros scattered, some blocked behind barricades fighting other Hassaikai.
"Sir!" Finding the strength in your legs sore from the earlier fall you ran to him. But he waved you away, his eyes shining with the knowledge of what was about to happen.
"Get out of here!" He yelled again, and when your gaze met him as stakes of concrete rose from the ground again, you swore he knew exactly what your future held.
He was trying to protect you. Really protect you. Not because he was a hero or because his duty and honor would be on the line. Because he knew you. Because he saw a child who'd been through enough and deserved a chance at her own happiness. You and Eri both.
And just as you were about to run to him anyways, a stake of concrete drove right through his body- the sounds of his clothes and flesh tearing numbing all others.
You froze seeing his blood splatter the floor, your face deadpanned. Everything else, like the second you woke, became muffled. The only difference was your sight now crystal clear as you couldn't look away from the sight of your mentor getting murdered.
"Nighteye," you breathed, and just as you did as a child, you'd never felt more helpless in the face of such carnage.
"Y/n, stand back, please!" Deku yelled, grabbing you by the shoulders as the monstrous mass of flesh that had become Overhaul set his sights on you instead.
Whoever got in his way of securing his war, of securing Eri was an enemy. And you were the one that started all of it.
Using his quirk to feel the chemical bonds holding the ground together below his hand, Chisaki chose to not honor his deal with the leader of the league. Driving a wall through the ground as he destroyed and rebuilt to a level you couldn't fathom, the man separated you and Deku.
Midoriya yelled the instant he was apart from you. He could barely breath he was running and kicking to avoid getting pierced. But he made a promise to Kachann, a promise to Todoroki, to you, to himself and he wouldn't break it so easily.
However, he couldn't know that Overhaul didn't just create a barrier to fight you more easily. He created a barrier so you'd just be easier to kill. And even if a quirk doesn't define your level of strength- In a state where you can only stare at the blood of someone you're about to lose without the protection of some sentient being such as Atomic... you're so vulnerable it takes nothing but a piece of concrete to the head to kill you.
Overhaul sighed below his mask, wondering how angry Tomura would really be if he just got rid of one especially annoying student. How much could it really matter? If the girl with the gray hair who just couldn't seem to stop getting in his way joined her mentor.
But just as he reached to touch the ground again, to drive a stake of concrete through your heart with his power, Overhaul felt something hit him upside the head from behind so harshly he stumbled over.
As he thudded to the ground, turned back around, what did he see but the two people who were meant to be working for him.
"We're really sorry birdman!" Toga yelled with a big smile, kicking him again this time right in the jaw as Twice threw her in the air. "But Shiggy explicitly said no hurting the students, and what did you do?"
"League scum," Overhaul grumbled, wishing it was them he'd tried to kill instead.
"How dare you!?" Twice said, jumping over the spikes Overhaul mounted as he dodged every which way Chisaki angrily sent his attacks. "We are extremely cool!"
Helping Toga across with him, Twice made his way to the other end of the battle where the heroes were fighting for their lives.
"Hello there!" He yelled, waving as you finally moved from your spot watching Nighteye, so lost in the overstimuli that you barely understood which way was up anymore.
After a moment of that, Toga grabbed your shoulders from behind to push you out of the way of more rubble heading straight for you while Twice picked you up in his arms. "We're rescuing you! Do not resist, please."
"C'mon Twice!" Toga started running, following the path Mimic accidentally made for them that was a perfect chance for escape.
And before you could comprehend what had just happened, who had taken you out of hell but the league of villains.
***
If you reread just the flashbacks. Everything should make sense now. :)
Oki, bye >...<