No one pov
Eraserhead is got beaten by the Nomu. The Nomu is on him, smashing his arms.
Tomura:You defeat Nomu, Eraserhead.
Suddenly a blue portal opened and a figure wearing a dark green armor, the same height as Eraserhead come. The atmosphere became cold and many begin to fear the figure.
Tomura:Who's that NPC?
A villain dashed at the figure. The figure just got a double barrel shotgun(where does Doomguy keep his weapons?), pull 2 shotgun shells and pull the trigger, killing the villain.
The villain fall dead on the ground. His blood painted the floor.
Tomura:He just kill him. What kind of hero is he?
Then he put the double barrel shotgun back and took a 1 barrel shotgun.
He goes and shot multiple times in the Nomu. The Nomu was hurt and the figure kick him from Eraserhead.
The figure goes to Eraserhead.
...:Are you alright, Uncle Sho?
Eraserhead:I...zu...ku?
Izuku:Yes. We'll talk after this. But call me Doom Slayer for now.
He used some med kit to help Eraserhead and pick him up and goes to the ones at the stairs.
Doom Slayer:Take care of him.
13:Who are you?
Doom Slayer:I'm Doom Slayer.
He cracked his knuckles and jumped in front of the villains.
Tomura:You'll pay for this!
Doom Slayer took his shotgun and looked at them before reload his shotgun.
Doom Slayer:Time to Rip and Tear until it's done.
The Doom Slayer AKA Izuku Midoriya.
Izuku was a happy boy, until he learned that he was Quirkless. His life took a 180 degree change. His step-sister, Izumi along with her friends(1A) started to bully him. Inko and his step-father neglected.
Having enough, at 14 he run away from his past. Then he encounter his Dad, Hisashi Midoriya AKA the Doom Slayer.
After learning about Izuku life,he wanted to have a chat with Inko and Toshinori,but he didn't.
He asked Izuku if he wanted his power. Izuku was hesitant at first, but he accepted. Hisashi give Izuku The Power of The Doom Slayer, resulting in Hisashi death. Izuku cried over the loss of his father, but promised to be strong. And from that day, Izuku become The Doom Slayer.