These fanfictions can make Bakugou seem more human. His being hurt shows that he's not invincible. For example, if he gets physically injured, it makes readers realize that he has limits, which can make his character more relatable. People might start to see him as more than just the tough, angry guy.
Some people write 'anti Bakugou fanfic' because they don't like his aggressive and bullying nature in the original story. They want to explore scenarios where he is held accountable for his actions more than in the official plot.
The teachers, especially Aizawa, would also be worried. Aizawa might give Bakugou special permission to skip classes or training until he's recovered. He'd also keep an eye on Bakugou's progress and make sure he's taking care of himself.
People like these fanfictions because it shows a different dynamic between Bakugou and Deku. Usually, they have a more competitive or combative relationship in the original work, so seeing Bakugou be caring is a fresh and interesting change.
Bakugou might react with his usual anger. He could lash out at the bullies verbally or even physically, which might make the situation worse. For example, if someone makes a snide comment, he could respond with a loud and aggressive retort.
One idea could be '5 Times Bakugou Saved the Day'. It would show his heroic side as he uses his powerful quirk to rescue people in different dangerous situations. Another idea is '5 Moments Bakugou Realized His Mistakes', which would focus on his character growth.
A '5 times bakugou fanfiction' could be really interesting. It might explore five different emotional states of Bakugou. One time could be when he was extremely angry and how that affected his actions. Another time could be when he was vulnerable, perhaps after a difficult battle. Then there could be a time when he was happy and celebrating a victory. And two more times could be related to his growth as a character, like the first time he realized he needed to change his attitude towards his friends, and the second time when he actually made a significant change in his behavior.
Midoriya is often a common character. Since he has a complex relationship with Bakugou, his reaction to Bakugou's expulsion can be an important part of the story. All Might might also be included as he could be a mentor figure who tries to guide Bakugou, even after his expulsion. And Bakugou's other classmates like Kirishima would likely be there too, as they are his friends and would be affected by his leaving.