Blood is thicker than water... yeah right.

The beginning...

Age 4- POV Izuku
.... yawn... IT'S TODAY!!!! I'm finding out my quirk, I wonder if I'll get mommy's or daddy's? Whatever it is I can't wait!
"Izuku honey come on we have to go, get dressed and come downstairs."
"Okay mommy"

Time skip to quirk doctor
"Hi what can I do for you today?"
"It's Izuku's birthday, we came to find out his quirk." Her voice wavers slightly as she gives a wobbly smile.
Mommy looks nervous I should make sure she's okay. "Mommy my quirk is gonna be just like your's, don't worry." I give her my brightest smile, but if anything she looks even worse.
She looks to the doctor "Please do the tests now." Her voice sounded desperate, what's wrong with mommy, I'll have to ask daddy when he get home from work with my brothers.

After the tests- POV third person
"May I ask what his parents quirks are?" Dr Tsubanasa asks.
"I have a strong telekinesis quirk and his father has something called black whips, they can come out of his body and become as hard as diamond." She says looking pale and close to tears.
"I see, well either one of you isn't the parent of this child or there was a mutation in the quirk gene. Your son has a quirk called Angel/Devil, In his Angel form he has white wings and a halo as well as an extremely strong healing ability. In his Devil form he has black wings, horns and a tail, he can control and bring shadows to life. In both forms he can harden his feathers and detach them to use as weapons as well as being able to control them mentally.
I've already informed your husband."
During this Inko had been getting paler and paler, at the end she thanked the Doctor, grabbed Izuku and rushed home panicking. She had cheated on her husband and gotten pregnant, a known Villain with a criminal empire he gained by killing viciously and with no mercy.
"Izu baby I need you to  your room and pack some clothes into your backpack, go quickly."she practically shoved him up the stairs and rushed to her room, frantically throwing clothes and jewels into her bag. She couldn't hope for mercy, her husband would never believe a gene mutation and Izuku looked nothing like him or his brothers.
BANG
"INKO YOU SLUT, GET DOWN HERE. WHO WAS IT, I KNOW YOU'RE HERE DON'T MAKE ME COME TO YOU." Hizashi roared shaking the house with his thumping steps and fury as he ran upstairs looking for his traitorous wife.
Shaking Inko looked to the doorway as he got to their room "Please, Hizashi, I promise I didn't cheat ple-"
SLAP
"SHUT UP WHORE, YOU'RE WORTHLESS AND YOU'LL PAY FOR MAKING ME LOOK STUPID." Hizashi grabbed her by the hair dragging her to the stairs before throwing her down them.
"Daddy?"Izuku looked up at him with a quivering lip and silver lining his eyes.
"SHUT UP BASTARD, GO TO YOUR MOTHER AND DON'T CALL ME THAT. "
Izuku ran downstairs where Inko was laying down, shaking with fear, she could only watch as Hizashi activated his quirk and walked towards her with hate in his eyes. Desperately she grabbed her son and hid behind him.
"Hizashi please take him instead, I'll do anything please." She begged shoving her shaking son in his direction.
He stopped "Anything?" He asked a thoughtful look on his face.
"Yes" she looked at him hopefully tears pouring down her face.
A wicked grin split across his face "then die" he pierced her with is black whips, his smile only growing at her agonised screams.
In her last moments she looked to her son and said her last 'loving' words "It's all your fault you monster". 
Izuku looked at her sobbing "Mommy I'm sorry I'm sorry." The words barely legible through his sobs.
Hizashi grabbed the bastard by the arm dragging him to his car before leaving, small bloody footprints being the only evidence he was there, and the last sign of him for many years.