If Naruto saved the Uchiha clan, the story of the Hidden Leaf Village would be rewritten. The history of the Uchiha's massacre would no longer be a dark stain on the village's past. The Uchiha would contribute their unique skills and abilities to the village's development. For example, their Sharingan abilities could be used for better security or in battles against common enemies. There would also be a change in the relationships between characters. People who were once enemies of the Uchiha might have to learn to work with them.
One great 'Naruto and Madara Uchiha' fanfiction is 'The Redemption of Madara'. It offers a unique take on how Madara could have been redeemed in the Naruto universe. It has a great plot that keeps you hooked from start to finish.
Well, in such a fanfiction, Madara's training might enhance Naruto's physical strength. He could teach Naruto some advanced Uchiha techniques which Naruto can combine with his own Uzumaki powers. For example, Naruto might learn better chakra control from Madara, enabling him to use his Rasengan more effectively and with less chakra waste.
The Uchiha might initially be filled with anger. Their trust in Naruto, if it was there before, would be completely shattered. They could start to plot revenge against Naruto, believing that he has wronged them. This could lead to a lot of tense moments in the fanfiction as the Uchiha gather their strength and resources.
In some fanfictions, it might be possible for Naruto to be portrayed as Madara Uchiha's grandson. Fanfiction often takes creative liberties and twists established relationships. However, in the original Naruto storyline, there is no such relation.
One great 'Naruto Madara Uchiha Crossover Fanfiction' is 'The Uchiha's New Path' on FanFiction.net. It combines Madara's power with an alternate universe concept where he teams up with characters from other anime. It's really interesting to see how his skills and personality interact with new characters.
In most Naruto fanfiction, anything can be possible. However, in the original Naruto series, Naruto has no relation to Uchiha Madara in this way. But in some creative fanfictions, the author might create a complex backstory to make Naruto be Madara's grandson. Maybe they rewrite the history, or use some magic - like elements to connect them.
In fanfiction, Naruto and Madara Uchiha's sister could be connected in various ways. For example, she might be a secret ally who helps Naruto understand the Uchiha clan better. Maybe she has some long - lost knowledge about the Sharingan that she imparts to Naruto to help him in his battles.
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.