Well, Naruto himself might be really focused on Pain's motives in the fanfiction fight. Since he always tries to understand his opponents. Sasuke could be analyzing Pain's jutsu and thinking about how it compares to his own power. And Sakura might be worried about the destruction caused, just like she was in the original story when Pain attacked the village.
In some fanfictions, Naruto's pain might manifest through his actions. For example, he could become withdrawn and isolate himself from his friends. This is because Naruto has always been a social person, so any deviation from his normal behavior could be a sign of his internal pain.
Some characters may gain new respect for Pain's power. If the fanfiction shows Pain in a more complex light, characters like Naruto could start to see him not just as an enemy but as a complex individual with his own reasons for fighting.
One possible cause could be his sense of failure. Naruto always wants to protect his friends and village, so if he fails in a mission or is unable to save someone, it can cause him great pain.
In a fanfic where Naruto gets killed by Pain, it's a dark turn of events. The story would then likely focus on how the remaining characters cope. For example, Kakashi might feel a great sense of guilt for not being able to protect Naruto. Hinata would be heartbroken. Moreover, the Nine - Tails would be left without a host, which could also lead to all sorts of problems. The ninja world would lose its most prominent symbol of perseverance and friendship, and it would be a very different world from the one we know in the original Naruto story.
Well, the Naruto vs Pain fight in the original series is epic. Fanfiction allows fans to explore different scenarios and what - ifs. Maybe they want to see different character developments during that intense battle.
Fanfiction explores the relationship of the Naruto Pain Brothers in various ways. Some stories focus on their loyalty to each other. For example, in many fanfics, we see how they would sacrifice for one another. They are often depicted as having a deep, unbreakable bond that was formed through their shared experiences.
It happens after a significant amount of time spent on character development and side plots. Naruto returns when the story arc demands his presence for the next major conflict.
Well, in the original Naruto story, Pain's actions are somewhat more straightforwardly presented as villainous. But in the fanfic, it might humanize Pain more. It could show his past traumas and how they led him to his extreme beliefs and actions.