Sanji would go all out in cooking the most nutritious and delicious meals for Usopp to help him recover. He might also be a bit overprotective, not allowing anyone to disturb Usopp while he's eating. Chopper would be in full - on doctor mode. He'd be constantly checking Usopp's vital signs, giving him medicine, and trying to figure out the cause of the sickness. Robin would be quietly researching any possible cures or causes, using her knowledge of history and ancient texts.
Well, Bruce could leave in fanfic for the sake of self - discovery. He's constantly struggling with his identity as Bruce and as the Hulk. Fanfic authors might write him leaving to find a place where he can better understand himself without the distractions and pressures of the Avengers team.
In some fanfictions, Regina might leave Emma for Robin because of a deeper emotional connection she feels she has with Robin. Maybe she sees in Robin something that she feels is lacking in her relationship with Emma, like a more traditional form of love or a different kind of understanding.
He could leave because he doesn't fit in. Naruto is all about the ninja way, with its own code of honor and fighting style. The Justice League's superhero culture is just too different.
In some fanfiction, Peter Parker might leave the Avengers because he feels out of place. Maybe he realizes that his style of heroism doesn't quite fit with the more organized and sometimes bureaucratic way the Avengers operate. He could also leave due to personal reasons, like wanting to focus more on protecting his local neighborhood in Queens rather than getting involved in global Avengers - level threats.
There are fanfictions where Issei leaves to protect others. He might learn of a great danger that is coming and decides that the best way to keep his friends and loved ones safe is to remove himself from the situation. So, he leaves, hoping that the enemy will follow him instead of targeting those he cares about.
One reason could be personal growth. Tony Stark is a complex character. In fanfiction, he might leave to explore his own identity outside of the Avengers. He could be seeking self - discovery, away from the constant superhero battles and group dynamics. He might want to focus on his own technological advancements or personal relationships without the interference of the Avengers' responsibilities.
Well, in fanfiction, the writers often explore different character arcs. Tony Stark could leave the Avengers because he wants to pursue a different path. He might have new goals that don't align with the Avengers' mission. For instance, he could be more interested in exploring new technologies for the betterment of the world on his own terms, without the constraints of the Avengers' group dynamic and decision - making processes.