Bakugou may prove his love by being protective. He might put himself in danger to save Deku. In many stories, this kind of self - sacrifice is a strong indication of love. Also, he could start to understand Deku's dreams and support him in achieving them, which is a deeper form of love than just friendship.
In the fanfic, there might be a moment where Bakugou is seriously injured but still tries to encourage Deku to keep going and not worry about him. This selfless act of putting Deku's well - being and future above his own pain is a strong indication of his love. Also, when Bakugou starts to train with Deku privately to help him improve his skills, it shows that he wants to see Deku succeed and is willing to invest his own time in it.
One possible motive could be a long - held grudge that has festered over time. Maybe Bakugou's constant bullying in their past finally pushed Deku over the edge. Another could be some sort of mind - control or dark influence that made Deku act out of character.
Some characters might try to understand Deku's motives. Kirishima, who was close to Bakugou, would be angry at first but might also try to find out if there were any extenuating circumstances. However, many would be afraid of Deku, seeing him as a threat now that he has killed one of their own.
The relationship could start with hatred. Bakugou may initially be enraged that Deku has become a villain. But as time passes, he starts to see the reasons behind Deku's transformation, which could lead to a more complex relationship.
Bakugou could use his words. He might tell Deku that he believes in him. For example, he could say 'Deku, you may be a nerd but you're a strong nerd.' It's a backhanded compliment but it shows he has faith in Deku.
Deku might be initially shocked. He's used to Bakugou's aggression, but an actual injury is different. He could be in pain and disbelief at first. Then, he might try to downplay it, especially if he doesn't want to cause trouble for Bakugou, because Deku is generally a very forgiving character.
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.
Well, it could be because some fans see a complex and often tense relationship between Deku and Bakugou in the original story. In the series, Bakugou has bullied Deku in the past. So, some fans might explore this darker side of their relationship in fanfiction, imagining that Deku could hold deep - seated hatred for Bakugou due to all the past abuse.
One common theme is revenge. Since Bakugou has bullied Deku, in these fanfictions, Deku might seek revenge on Bakugou for all the pain he has caused. Another theme could be self - discovery. Deku may realize his own strength and worth through his hatred for Bakugou and break free from the shadow of being bullied.