His grandfather could be a bit of an outcast in the village, like Naruto was initially. This would create a strong bond between them as they both understand what it's like to be different. He might have some unique ninja abilities or knowledge that he passes on to Naruto, which makes Naruto stand out even more. And he could be very protective of Naruto, shielding him from the harsher aspects of the village until Naruto is ready to face them on his own.
Maybe his grandfather is a laid - back but wise old man. He would teach Naruto about life and ninja values in a more patient and gentle way. He could have a lot of stories from his own adventures as a ninja that he would share with Naruto, which would inspire Naruto in different ways compared to the original story. He could also be someone with a lot of connections in the village, which would help Naruto in his growth as a ninja.
His grandfather could be a very strict and traditional ninja. He might have high standards for Naruto in terms of ninja skills and discipline.
It could be an old and powerful wizard who has been in hiding for years. Maybe he was a friend of Dumbledore's but had some differences with him, so he stayed away from the main events in Harry's life until now.
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.
If Naruto was raised by his grandfather, he might have learned different jutsu earlier. His grandfather, with more life experience, could have trained him better. Also, Naruto's relationship with the village might be different. He might be more respected as his grandfather could have a certain standing in the village, and this could change how people view Naruto from the beginning.
In this kind of fanfiction, Naruto might learn a lot of hidden family secrets. His grandfather could teach him some long - lost jutsu that was unique to their family. Maybe his grandfather would tell him stories about the early days of Konoha, which could give Naruto a new perspective on the village he loves so much.
Well, perhaps the grandfather could be teaching Harry all kinds of magic that his parents didn't have the chance to. He might introduce Harry to a different side of the wizarding world, full of old family secrets and forgotten spells.
Perhaps Madara's grandfather was a diplomat of sorts for the Uchiha. He might have been involved in negotiations with other clans or villages. This would explain how the Uchiha managed to hold their ground and gain influence in the ninja world at that time. He could have used his wisdom and charisma to form alliances and avoid unnecessary conflicts.
One possible plotline could be that Harry's grandfather imparts unique magical knowledge to him that he doesn't get at Hogwarts. Maybe it's an old - fashioned kind of magic that has been forgotten over time. This could give Harry an edge in dealing with the dark forces.
One possible plot could be that his grandfather, perhaps a powerful but reclusive wizard, trains Harry in unique magic from a young age. Harry might grow up with a different set of values and skills compared to the original story. He could have a closer bond with the wizarding world's older traditions.
They might be similar in appearance. For example, they could have the same eye color or the shape of their nose.
Harry could develop a more unique style of magic. His grandfather might have his own way of doing magic, and Harry would learn from that. For example, his grandfather could be more in tune with nature magic, and Harry would then incorporate that into his spell - casting, making his magic more diverse and less reliant on the traditional Hogwarts curriculum.