Uraraka would be heartbroken. She was one of Deku's closest friends. She might lose some of her usual cheerfulness and become more focused on finding out who or what was responsible for his death. She could also struggle with her own self - confidence in using her quirk, as Deku was always an inspiration to her.
Well, I'm not sure about a specific 'deku x bakugou dies fanfiction' that is the best. However, many fanfiction writers might explore this concept in different ways. Some might focus on the emotional aftermath for the other characters, while others could create alternate universes where this event leads to a whole new set of adventures or challenges for the remaining characters in the My Hero Academia universe.
One popular 'deku dies' fanfiction might be those that explore the impact of his death on the other characters in the My Hero Academia universe. For example, it could show how his friends like Bakugo or Ochaco react to his sudden demise. They might struggle with guilt, as in some stories Bakugo has bullied Deku in the past. His death could also be a catalyst for change in the hero society, making heroes reevaluate their values and the way they protect civilians.
You can also try Fanfiction.net. Although the interface might not be as modern as AO3, it still has a vast amount of fanfiction. Search for the relevant keywords there too. Additionally, some Tumblr blogs might also share or recommend such fanfictions. You can search Tumblr using relevant tags like #deku x bakugou dies fanfiction.
In this fanfic, it could be that Deku's quirk goes out of control during a training exercise. He loses the ability to contain his power and it ends up consuming him, resulting in his death. This would create a lot of self - reflection among the other students about the risks of their quirks and the importance of proper training and control.
Bakugo would be deeply affected. He might initially deny his feelings, but then would be filled with guilt for all the times he was mean to Deku. He could become more withdrawn and focused on becoming a hero worthy of Deku's sacrifice.
Well, sometimes in these fanfictions, Deku's death can lead to a split in the hero community. Some might think that the way heroes operate needs to change drastically because Deku, who was seen as a symbol of hope, died. There could also be a plot where Deku's mother has to deal with the loss, and this could show a more human side of the story. And, his death might inspire a new generation of heroes who didn't know him personally but were inspired by his story to step up and fill the void he left.
Writers sometimes have the characters' emotions lead to character development. For example, Bakugo might become more empathetic after Deku's death. He could start to understand the value of Deku as a person and a hero. Other characters could also find new motivation in their grief, vowing to carry on Deku's ideals in his memory.
The story's tone becomes much darker. Without Deku, the positive and hopeful energy he brought is gone. The whole mood of the fanfiction turns somber. It's like the light has been snuffed out in the hero world.