Premise

Follow the adventures of Izuku Midoriya, a powerless kid trying to make his way to the top in a world full of hunters and heroes, while taking care of his sister.
What would happen if a quirkless kid got the power to level up by killing? In a world where dungeons are an everyday occurrence, this would be awesome.
Watch as this kid goes from one of the weakest to humanity's defender and the shadow monarch, saving people and killing bad guys.