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.
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.
To some extent, it is popular. There are many online platforms where MHA adult fanfiction can be found. The popularity might stem from the fact that the MHA world has a rich cast of characters and a complex universe. Fans who enjoy adult - oriented storytelling might use these characters to create their own narratives that are more in line with their interests in terms of relationships, power dynamics, and personal growth, all with an adult twist.
Several characters have met their demise in the MHA manga, but it's a bit complex to list them all precisely. Some of the notable ones include [mention specific characters if known].
I think it's hard to say for sure. There are a few characters who could potentially be the traitor, and it's all part of the mystery and suspense of the story.