One interesting plotline could be Deku having to face off against his classmates in a series of challenges that test not only their quirks but also their teamwork and strategic thinking. Maybe there's a misunderstanding that leads to the conflict.
They could develop a symbiotic relationship. Maybe Nomu has a power that All Might needs to defeat a greater evil, and in return, All Might helps Nomu to become more than just a mindless weapon. This would require them to trust each other, which is a unique take on their relationship considering their normal opposing natures. Also, the story could explore how their relationship changes as they face different challenges together.
Deku himself is likely to shine. Given his powerful quirk and his growth throughout the main series, he'll surely put up a great fight against his classmates. Bakugo could also shine as he's always been in competition with Deku and has a very strong quirk.
One interesting aspect could be the different interpretations of the characters' powers. In fanfiction, the author might explore new ways Deku uses his One for All ability against Overhaul's powers. It can also show different battle strategies that might not be in the original manga or anime.
You can try looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. These platforms usually have a wide variety of fanfictions, including ones related to 'Deku vs Overhaul'. Just use their search functions to find what you're looking for.
Well, in such a fanfiction, Izuku might end up in a coma. His friends would be really worried. Ochaco might constantly visit him in the hospital, hoping he wakes up soon. And Bakugo could have a change of heart, realizing he should have been nicer to Izuku all along.
He would likely feel a sense of failure. Since Izuku has such a strong drive to be a hero, being hurt by the Nomu might make him think he's not good enough yet. It could be a big blow to his self - confidence.
A really interesting plot twist could be that Nomu was originally a human that All Might knew in the past. Maybe it was a student or a friend who was experimented on by the villains. This would create a huge emotional turmoil for All Might. He would have to deal with the fact that this once - familiar person is now a mindless (or not so mindless) Nomu. It would also add a layer of complexity to their relationship in the fanfic, as All Might would be torn between trying to save the person inside Nomu and having to fight against Nomu's actions if it's being controlled by the villains.
In a fanfiction, the Nomu could be controlled by a hidden villain who wants to break Izuku's spirit. So, the Nomu injures Izuku in a brutal way. This forces Izuku to re - evaluate his approach to heroism and his relationships with his friends and mentors. He may have to find new ways to heal and grow stronger, both physically and mentally.