Izuku and Shinso are twins to the powerful villain, AFO/Hisashi, a hero killer, Stain, and someone who's considered human but at the same time, considered a Nomu, Kurogiri/Oboro.
Two people have heard of the twins, Inko and Toshinori Yagi. Inko was not capable of having children of her own, which is probably why she originally stole the two twins. Izuku would stand up for his twin, despite his twins' protest.
When Stain woke one day to his sweet angles gone, he whimpered loudly, making his other child, Tenko, come in and rush over to him. He asked what was wrong and his papa told him in a shaky voice that his twins were gone. Now, Tenko, was upset and vowed to find them.
When the others found out, they went to look for the twins. That search will never stop until those two were found. Izuku had lost his spark when he was ten. He was also very innocent unlike his brother. He tries to not infect his brother with it though. When the twins were about 14, Toshinori's old friends were coming. More specifically, Hawks and Midnight.
When Midnight and Hawks get to the house, they were hit with an omegas scent. And they were just at the door, not inside. Hawks knocked, a male omega who's spark was gone answered. That was already a red flag for the two heroes.
What happens when Izuku and Hitoshi find their mates? Hitoshi wanting his brother and himself out. What about when Izuku saves a hero from a Nomu? The said hero he saved, one of his mates? What if the hero tried to follow him but lost track of him and his scent? What will the villains do when someone took down the Nomu and realize that they seem familiar to the said villains? What if Izuku saw his other mate in the shadows one night? What if he got away from that soulmate as well?
"We have to go, Izu. Now."
A hand sticks out from the ground, reaching, reaching-
A purple fog appears.
"-ave to go, Izu."
A suited man approaches, hand outstretched.
"Let me help you, child."
His hands slide away from his mom, and takes the man's hand.
"There's no time!"
____________________
"Kid?"
The child doesn't move, doesn't even make a sound. Aizawa immediately assumes the worst.
It's likely the kid could be dead.
Aizawa cautiously moves towards the white-blue haired boy. He crouches down and pulls his boney wrist up, taking his pulse. There's a steady beat. He sighs in relief and realizes there is something crusting off of the child's hand and wrist. Blood.
Aizawa inspects the kid's arm, then shoulder, but there is no visible wound. The only indication that the child is injured is a swollen, dark purple bruise around his eye with hints of sprinkled yellow patches.
He makes a quick call for the ambulance, then gives him one last shake, seeing if he'll wake up.
He doesn't stir.
Aizawa scoops the kid up bridal style and sets off to hand him over to the paramedics.
He won't fail another innocent child.
OR:
This is an alternate reality where young Tenko Shimura (Shigaraki) was helped by our favorite yellow caterpillar (Aizawa), and given a chance to be a hero. Meanwhile, in Musutafu, Japan, Izuku Midoriya has been given a helping hand by the wrong person. What happens when Izuku and Tenko have their roles reversed?
Creds to @Firely123 for the amazing cover!