One possible plot could be that Naruto, after dying heroically in his own world, is sent to the Soul Society. There, he discovers his new spiritual powers as a Soul Reaper. He might struggle at first to adapt to the new rules and hierarchy. He could meet old friends in spirit form and together they train to become strong Soul Reapers. Naruto's determination and unique ninja skills might give him an edge in this new afterlife, and he could end up facing some great evil in the Soul Society, using his newfound powers in unexpected ways.
It could be a powerful Hollow that has somehow broken free from the normal Hollow hierarchy and is causing chaos in the Soul Society. This Hollow might have a special ability that makes it difficult for the Soul Reapers to defeat it, and Naruto, as the new Soul Reaper, has to figure out a way to stop it.
Well, it could be that she discovers hidden secrets about the afterlife and has to make difficult choices. Or perhaps she forms unexpected friendships with other supernatural beings.
Yes, there are quite a few. You can find them on various fanfiction websites. Some might focus on Naruto somehow getting the powers of a Soul Reaper and how he uses them in the Naruto universe. For example, he could use Soul Reaper abilities like Zanjutsu to fight against the Akatsuki.
He might have a long, dark cloak similar to the traditional reaper look. His hair could stay the same, but perhaps with a more ethereal glow. And his eyes might turn a different color, like a deep purple, to signify his new role.
Well, if Naruto becomes the reaper in fanfiction, he would probably have a whole new set of powers. He could start reaping souls in the Naruto universe, which would be a huge change. Maybe he'd use his new reaper abilities to deal with the more dangerous enemies in a different way, like sending their souls to some sort of afterlife realm.
Well, it could be about a fictional academy where characters from Naruto and Soul Reaper universes come together. Maybe it has students learning special skills from both worlds, like Naruto characters learning about soul reaping and Soul Reaper characters learning ninja techniques.
One main theme is power combination. Naruto's ninja abilities combined with Soul Reaper powers. Another could be the exploration of different worlds. Naruto traveling between the Naruto world and the Soul Society.
It could be Naruto and Ichigo. Since it's a crossover of the two series, these two popular protagonists would likely play important roles in the fanfiction.
It could be Naruto himself, if the fanfiction is about him obtaining Soul Reaper powers. Maybe Sasuke could also be involved, perhaps as a rival who also gets some sort of power related to Soul Reapers. And there could be characters from the Soul Reaper side like Ichigo making an appearance in the Naruto world.