Izuku is the son of Hisashi Midoriya and Inko. But Hisashi left for a few month to help his friends, Goku and the others Z fighters.(Hisashi is a Sayan)
What he didn't know is Inko cheated on him with Toshinori Yagi. Hisashi wanted to kill them, but he didn't wanted to reveal that he's a Sayan. So he leave, the Hero Comision didn't allow him to take Izuku with him.
After many years, Izuku got OFA because he didn't know he was a Sayan, he thought his tail is a mutation.
Izuku was framed by LOV and his friends(1A were childhood friends) didn't believe in him, Inko disowned him, Toshinori took OFA and give it to Izumi. Only 1B, the rest of the teachers, aunts and Uncles believed in him.
Izuku was sent to Tartarus.
There he was beaten by the others inmates where he was put in a coma.
Izuku(thought) :They betrayed me. I risked my life for them. I'll make them pay for everything they did to me.
Just then Beerus and Whis appear.
Beerus:Then what are you waiting for?
Whis healed and they teleport to the Z Fighters. Hisashi reunited with his son and explained everything.
Time skip
Champa challenge Beerus to another Tournament.
Now Izuku is against Caulifla
(Izuku clothes)
(Izuku change his hair style to this, he still has green hair)
Caulifla:So, they have another Sayan? Let's see how long can you last. Aaaaaagggghhhhhh!
Caulifla transformed in Ssj3.
Caulifla:Come at me at full power.
Champa:Take that Beerus! You'r Sayan is weak against Caulifla who's now Super Sayan 3.
Beerus yawned.
Beerus:Oi, Izuku. Show them you'r Super Sayan 4.
Champa/Caulifla:Super Sayan 4?
Izuku:You got it, Lord Beerus. Aaaaaaahhhhhh!
Izuku transformed into Super Sayan 4.
Caulifla:What an immense power. Hah! Is this Super Sayan 4?Champa:What is this transformation?
Caulifla:I never believe it that'll be a Super Sayan 4. I'll train hard to unlock it.
Izuku:Unfortunately you can't become Super Sayan 4.
Caulifla:Huh? Are you kidding me?
Izuku:Because the Sayans from you'r Universe and you aren't born with the tail. A Sayan wouldn't never have Full Power without his tail.
In a split second, Izuku dashed and Caulifla didn't see him.
Izuku knocked her out with a powerful punch in the stomach.
Izuku won and returned to his base form.
Beerus:Well done, Izuku.
Izuku:Thank you, Lord Beerus.