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.
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 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.
Well, it could be about a fan - created story that combines elements of Naruto and Soul Reaper. Maybe it has a character from Naruto who gains powers like a Soul Reaper, or there are crossovers in the plot where the two universes interact in unique ways.
One possibility is that Naruto enters the world of the Grim Reapers. He could struggle with the new rules and ethics there. Since he was always about protecting life in the ninja world, now he has to deal with death. He might face challenges from other reapers who don't trust this newcomer from another realm.
Naruto would probably develop a deeper understanding of life and death. He's used to fighting to protect life, but now he's on the other side. This new perspective could make him more empathetic towards all beings. He might also become more mysterious to those who knew him before, as his new role would be so different.
Well, if Naruto had Soul Reaper powers in fanfiction, it would completely change the way he fights. He could use zanpakuto techniques instead of his regular jutsu. For example, he might be able to use Getsuga Tensho instead of Rasengan. His physical abilities would also be enhanced in a different way, more like a Soul Reaper's. And his relationships with other characters would shift too. His friends might be a bit in awe or even a bit scared of his new powers at first.
In this fanfiction, Naruto's death could be a sacrifice. As a hollow, he could start off being very confused. His ninja skills might be warped in this new form. For example, his Rasengan could turn into some sort of dark energy blast. He might also meet other characters from the Naruto world who have also had strange after - deaths, and together they try to find a way to either move on or return to their normal state.
Perhaps it's a rogue Shinigami who doesn't want Naruto to figure out how to control his new form. This Shinigami might fear that Naruto could disrupt the balance between Hollows and Shinigami if he becomes too powerful in his hollow state. So, he tries to stop Naruto at every turn, creating a lot of conflict in the fanfiction.