Oc/Reader is male. He is in his late 20s early 30s. His quirk is Like Homelander (The Boys. They is descriptions about his quirk under his life and the kids he adopts)

He lived in America and was 1st in the rankings. But he moved to Japan after an incident. (OR he has always lived in Japan you Choose)

He is a pro hero.  He has adopted Izuku, Shoto, shinso, Kota and eri.

He was Flying home when He heard a Child screaming and adults yelling Curses at the child.

He breaks down the door and finds a purple haired child as adults try to put a muzzle on him.

He stops the parents and holds the child as he calls the cops.

The boy name is Shinso and he becomes attached, and won't leave him so he is allowed to adopts him.

Months later he is at a car crash scene where he finds a green haired boy trying to wake His mother who was dead.  Izuku becomes attached and he adopts him aswell.

Months later He saved shoto , Natsuo and Fuyumi from endeavour. But the hero commission wouldn't arrest him all they did was remove him from the rankings. And he can't have contact with shoto, Natsuo and Fuyumi without their permit.

Since Natsuo and Fuyumi are older they wanted to live with each other and Fuyumi got custody.

But shoto was just a Toddler after he got burned by his mother. And he became attached to Reader/Oc and since he already had adopted kids he was allowed to adopt him.

He was friends with waterhose and he had gave them a Supersonic device that only he is able to hear. They use it when fighting muscular.

He arrived in a couple minutes after they activated the device and then defeated muscular And used his heat vision to blind him in one eye and knocking him out and giving him to the police before flying waterhose to a hospital but they had been injured to badly they died on the operating table.

Waterhose before they died made him promise to adopt Kota. So he did. Kota was only a baby when he adopted him.

When Kota was old enough he told him what happened. Kota still hates heros except for Reader/Oc as he tried to save his biological parents.

His kids are very close to him and eachother. They consider him as their Dad and eachother as siblings.

With all of his kids wanting to be heros except Kota. He helps them train with and without their quirks. And teaches them self defence.

And he told izuku he Would love for him to be a hero without a quirk but as he was a hero he sat down with him and told izuku that without a quirk he would be killed. (Izuku understood as he actually told him all about the things he has seen as a hero and hoe it is extremely dangerous)

but izuku still wanted to be a hero so he tried to train him in self defence but when sparring with shoto and shinso with quirks he wasn't able to defeat them he could only beat them when they sparred without quirks.

Oc/Reader helps izuku save Eri and then he adopts her.

(Quirk is like Homelander From the boys)

Normally a child will have to be four for their quirk to appear but when Reader/Oc was a child as his mother was giving birth his quirk appered and he accidentally killed his mother.

His father hated him and gave him away to an underground Laboratory that experimented on kids with powerful quirks.

As a child in the Lab he broke a woman's spine by hugging her.

They tourted him and made him kill people. Even making him fight people they brought in sometimes even other kids and he had to kill them otherwise if he didn't they tourted them infront of him,  so he tried to kill painlessly by snapping their necks.

And his quirk had a Quirk awakening improving his quirk hugely and when his quirk improved he went on a rampage and killed all the scientists in the lab.

He was the only child to survive the experiments

His quirk is a mystery to him, as he has super strength, super speed, Heat vision, flight, durability, super Hearing, Super vision and X-ray vision.

Superhuman Strength: One of Reader/Oc primary abilities is his tremendous superhuman strength.

After he intercepted a robbery, he threw the first thief far away and high into the air then Captured the other theifs before catching the one he threw in the air. 

He also easily pushed open a door blockaded by scaffolding with one hand and embedded his hand through a steel wall.

He easily overpowered a villian lifting them off the ground with one hand.

In a fit of anger, he threatened to pull Shigiraki apart limb by limb.(USJ)

He casually killed a nomu by crushing its head. (USJ)

Superhuman Durability: He is very resistant against physical harm.

He is not only completely bulletproof but also unfazed by explosions.

While pursuing A powerful criminal He survived having a building dropped on top of him without any signs of injury save for being dirtied from the incident.

However his immense durability does indeed have limits. As the Nomu was able to make him bleed.

Superhuman Speed: While He can fly at extremely fast speeds, enough to keep up with an airplane he can also move on the ground at supersonic speeds.

He is fast enough to dodge bullets/Blasts and disarm multiple gunmen before they could even react.

Superhuman Stamina: He possesses stamina that is enhanced to inhuman levels. As a result, his muscles produce practically no fatigue toxins during physical activity. They are able to withstand the stresses of moving at superhuman speeds or performing other superhuman feats for extended periods of time, without tiring or becoming weak

Superhuman Hearing: He possesses tremendous auditory awareness, allowing him to detect sounds from miles away. He can also use this power to detect a person's heartbeat and blood pressure, and can tell when they are excited or anxious and his hearing also allows him to tell when someone is lying.

Heat Vision: He is able to generate red heat energy from within his eyes and can project it outwards as high powered beams. These blasts of energy are so powerful that they can cut through almost anything. He also used his heat vision to melt a thief's gun to the latter's hand.

He is able to control the intensity of the beams

X-Ray Vision: He can see through any solid object or surface with the exception of objects and surfaces that are lined with zinc.

Telescopic Vision: He can zoom in on things, allowing him to see distant objects, people and surroundings.

Supersonic Flight: He is able to levitate and propel himself at supersonic speeds, allowing him to cover vast distances in a matter of minutes.