Stop Nomu!

Izuku's mind raced frantically, before something clicked. What Shigaraki had said, about Nomu being a mindless bioweapon. That explained why his safety net hadn't protected Aizawa from Nomu. Crippling pain was worthless against such a thoughtless, obedient creature. Point being? There was no free will to violate with Nomu. So Izuku didn't have to worry about crossing his own lines here.

"Momo," he whispered to her quickly. "Listen carefully. I wish that this Nomu creature would become an attractive woman, still a bioweapon, same Quirks and everything, but looking fully human. And I wish for her to malfunction in a way that causes her to start obeying me instead of these guys. And to maintain secrecy, I want all memories and records regarding her background changed to make it make sense to everyone, including her makers, and current controllers. The only ones I don't want unaware of the change are those who are in on you being a genie."

Momo nodded, and immediately snapped her fingers. All Might blinked as he watched the monster change, becoming an attractive, muscular woman with short, dark blonde hair, green eyes, a moderately curvy figure and fair skin. Her shorts also changed into a set of green sports wear that left her arms and midriff exposed. Her expression remained vacant, showing absolutely no higher thought processes.

(https://www.deviantart.com/vin13ish/art/Blonde-Military-Girl-6-949757578)

Neither Shigaraki or Kurogiri showed any reaction to the change. As far as they were concerned, Nomu was always like that. Their memories changed to rationalize it as this particular model of the Nomus being kept fully human looking to blend in better with human society. Even with Mutant Type Quirks being fairly common, they still tended to draw attention.

All Might glanced towards Izuku, realizing he had had something to do with this. He smirked a bit, before turning back towards the Villains. "Nomu, finish them off!" Shigaraki ordered, and Nomu took a step forward.

"Stop!" Izuku shouted suddenly, forcing some acted desperation into his tone to sell the idea that the Nomu obeying him was something he was stumbling upon. To the surprise of everyone unaware of the change, she complied.

"Nomu, what are you doing? I said, attack!" Shigaraki demanded. But Nomu didn't respond.

"Um... Attack them!" Izuku said, pretending to be tentative about the order. Nomu immediately turned towards Shigaraki and Kurogiri as their eyes widened.

(Credit goes to the Quiet One for this idea.)