I really liked 'Karma and Bakugo: A New Path'. In this fanfic, the author delves deep into how Bakugo's actions in the past come back as karma and how he overcomes it. It has some really interesting plot twists and great interactions between the characters.
Another theme is growth. The idea of karma in these fanfics forces Bakugo to grow as a person. He has to become more empathetic and understanding, which is a big change from his initial brash self. This growth is usually shown through his interactions with other characters, like how he might start to be more collaborative instead of always being competitive.
The Bnha universe's reaction would be mixed. Those who are into complex stories, like Todoroki, might study the relationships in Hamilton fanfiction. But others, like Mineta, might not be interested at all because it doesn't have much to do with his usual interests. Overall, it would depend on the individual characters' personalities and interests.
Some would be inspired. Characters like All Might might see Peter Parker's journey as similar to his own in some ways. Both are trying to do good in a world full of challenges. All Might could appreciate Peter's determination to protect his city despite having a normal life outside of being a hero.
For heroic - centric fanfictions, they would likely be disdainful. Since they oppose heroes, seeing stories that glorify heroes would annoy them. They might scoff at the idealized versions of heroes in those fanfictions.
Deku would be devastated. He has always seen Bakugo as both a rival and someone he deeply cares about. His reaction would likely be a mix of extreme grief and guilt. He might feel that he could have done more to protect Bakugo. Kirishima, who is Bakugo's friend, would be heartbroken. He would probably be filled with anger towards whatever caused Bakugo's death and would be determined to make the culprit pay. Ochaco and the other classmates would also be in shock. They would come together to support each other through the difficult time, but they would also feel a great sense of loss as Bakugo was an important part of their class dynamic.
Maybe they could combine Naruto's Rasengan with Bakugo's explosive power. Picture Naruto forming a Rasengan in his hand and Bakugo adding his explosive energy to it, creating an even more destructive and concentrated attack. This would be a really cool combination in a fanfic.