Well, it could be about a story where a character, perhaps Naruto, is somehow related to the reincarnation concept involving Kisuke. Maybe it's a crossover where Naruto takes on some traits or a role related to Kisuke's reincarnation in a fictional universe created by the fanfiction writer.
It could be that Naruto is reincarnated as Kisuke Urahara. He then uses his Naruto - like determination and ninja knowledge to change things in the Bleach world. For example, he might teach some of the characters there his unique jutsu or his way of thinking about friendship and loyalty. He could also use Urahara's resources and intelligence to solve problems in a different way than Urahara usually does, adding a new dynamic to the Bleach storyline.
Obviously, Naruto would be one of the main characters as he is the one who is the reincarnation of Kisuke. And Kisuke himself, even if only in the context of his past life or the influence he has on Naruto. There might also be other Naruto - related characters like Sasuke, Sakura, etc., as they would interact with Naruto in this new situation of his reincarnation.
One interesting Naruto Kisuke fanfiction could be where Kisuke helps Naruto unlock a new and powerful form. Maybe he uses his unique skills and knowledge from his own world to guide Naruto in a different way of training.
I think Ichigo would be a great character to pair with Naruto in Kisuke fanfiction. Since Kisuke has a connection to Ichigo's story, and Ichigo's combat style and determination could match well with Naruto's. They could learn from each other and have some really cool team - up moments.
Yes, there are likely some 'naruto is kisuke urahara' fanfictions out there. You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). Just type in the relevant keywords in their search bars and see what pops up.
One possibility could be that Naruto is drawn to boxing because of its physicality and the determination it requires. He might see it as a new way to test his strength and endurance outside of ninja battles. Maybe he starts training with a local boxing coach who sees his potential and helps him develop his skills.
Perhaps Naruto's transformation into a Predator - like being changes his appearance. He might have some Predator - like physical features such as glowing eyes or enhanced strength. This could lead to his friends initially being scared or confused, but as they see him use these new powers for good, they come to accept him. In the story, he could also learn to control these powers, so they don't overtake his original ninja nature.
One possible scenario in a fanfiction where Naruto becomes Pein could be that Naruto is exposed to some dark jutsu that alters his mind. This jutsu might be related to the Rinnegan's power. As a result, he starts to adopt Pein's ideology of bringing pain to the world in order to create peace. His friends would be shocked and try to bring him back to his normal self.
Well, Naruto as a genie would be a really cool idea for a fanfiction. His character already has a strong sense of justice and a big heart. As a genie, he would be able to spread his positive influence even more widely. Imagine Naruto granting the wish of a poor village for food and resources. He could also use his genie powers to create illusions on a grand scale, fooling the enemies of the village. And his bottle or lamp (where he is trapped as a genie) could be hidden in some super - secret location in the Hidden Leaf.