There's also 'The Bond of Enemies'. In this fanfic, Pain, after his defeat, is given a second chance at life by Naruto. It shows a really interesting dynamic as Pain tries to figure out his new place in the world with Naruto's influence. It has some great action scenes and emotional moments.
It could be about Naruto having some sort of connection to Pain. Maybe in this fanfiction, Naruto is somehow related to Pain in a way that wasn't in the original story, like being his son in an alternate universe. This could lead to a whole new set of storylines, with Naruto perhaps having to deal with the legacy of Pain while also following his own path as a ninja.
Obviously, Naruto and Pain are the main characters. Naruto, the energetic and determined ninja from Konoha. Pain, on the other hand, is the complex antagonist with his own set of beliefs about peace through pain. Their interactions are likely to be the focus of the fanfiction.
Obviously, Naruto would be one of the main characters as it's about him being the son of Pain. Pain himself would also be a crucial character, even if he might not be physically present all the time. And characters like Sasuke, Sakura, and Kakashi would still likely play important roles as they are Naruto's friends and mentors in the original story and would have to interact with Naruto in this new, changed scenario.
A fanfiction titled 'Naruto's Admiration for Pain' is also worth checking out. It focuses on Naruto's growing admiration for Pain's power and ideology. However, Naruto also tries to change Pain's more extreme views. The story is full of intense dialogues and Naruto's internal struggles.
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, 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.
Perhaps in the fanfiction, Naruto and Pain team up against a greater threat. They put aside their differences as Naruto's ability to forgive and see the good in people makes Pain re - evaluate his own actions. This could lead to a whole new adventure where they combine their powers in unexpected ways.
Maybe Orochimaru's former followers who are still lurking in the shadows. They see Naruto as a threat and Hinata as an easy target to get to Naruto. Another possibility could be some power - hungry shinobi from other villages who view Konoha as weak after the Pain incident. They might target Naruto and Hinata as key figures in Konoha's future to try and undermine the village's rebuilding efforts.