He could be a powerful and respected shinobi from the Uzumaki clan. Given the Uzumaki's reputation for strong chakra and unique abilities, Naruto's grandfather might have been a key figure in the clan's history.
One idea could be that Naruto's grandfather was a great shinobi who had a unique jutsu that was lost over time. In the fanfiction, Naruto could discover some hidden scrolls that lead him to learn about this jutsu from his grandfather's past.
Yes, in certain fanfictions Jiraiya is indeed Naruto's grandfather. This alteration of the original Naruto storyline in fanfiction can create a whole new set of character dynamics. For example, it could mean that Jiraiya had a more direct role in Naruto's family history. It might also change how Naruto views his own family and his place in the ninja world. This kind of creative change in fanfiction can bring fresh perspectives to the well - known Naruto story.
His grandfather could be a very wise and patient man. He might have been the kind of person who was always calm in the face of danger, and Naruto could inherit some of these traits subconsciously.
In fanfiction, the possibilities are endless. Regarding Madara Uchiha being Naruto's grandfather, it could be a really cool and unique take. Maybe the fanfic writer has a great plot in mind where this relationship changes the whole Naruto story. For example, it could influence Naruto's powers, his understanding of the Uchiha clan, or even how he views the history of the ninja world. But of course, this is just a fanfiction idea and has no basis in the original Naruto plot.
I'm not entirely sure if there is a specific fanfiction with Naruto's grandfather being Madara Uchiha. But in the realm of fanfiction, anything is possible. Writers might be intrigued by the idea of mixing Naruto's story with the power and history of Madara Uchiha in such a way. It could lead to some really interesting plot developments, like how Naruto's character might be different growing up with such a powerful and infamous figure as his grandfather in the backstory of the fan - created world.
Another idea is that the fanfic delves into a what - if scenario. What if Naruto's grandfather had been able to change Madara's path? This could lead to a completely different Naruto - verse, where the Uchiha clan's history and the overall power balance in the ninja world are altered. The fanfic could then explore how Naruto's life and his journey as a ninja would be different in this alternate reality.
One consequence could be a stronger sense of family heritage for Naruto. He might inherit more than just skills from Jiraiya but also a deeper family legacy.
One implication could be in terms of Naruto's power. Since Madara was extremely powerful, Naruto might inherit some latent Uchiha abilities. Also, it could change Naruto's view of the Uchiha - Senju conflict. He might see it from a more personal perspective.
Some Tobirama fanfictions focus on his relationships with his brothers. It could explore how his bond with them influenced his decisions and actions. For instance, how the loss of his brothers affected his leadership style. These stories add more depth to his character, making him more than just a powerful ninja in the Naruto universe.