Often, Naruto might be paired with Madara in some sense. Their opposing views on power and peace could create interesting interactions in the fanfiction.
One common theme is power and ambition. Both Madara and Obito are characters with great power and strong ambitions in the Naruto series, and fanfics often explore how their relationship is influenced by these aspects.
The theme of redemption also appears. Given some of the actions of Obito and Madara in the Naruto series, fanfics sometimes explore if they can find redemption in their relationship with each other. They might try to make up for their past mistakes through their connection in the fanfic.
No. Naruto has his own unique story and character development that is distinct from simply being a fanfiction of Uchiha Madara. Naruto is about his journey to become Hokage, his relationships with his friends like Sasuke, Sakura, etc. His goal is to bring peace to the ninja world in his own way, through understanding and friendship. While Madara is an important part of the Naruto lore, Naruto's story is not centered around being a fanfiction of Madara. He is his own hero with his own dreams and challenges that are not directly related to being a fan of Madara.
Yes, there might be. The world of fanfiction is vast and full of crossovers. Fans often like to combine different fictional universes, so it's very possible that someone has created a story where Harry Potter is a fan of Madara Uchiha. You can search on various fanfiction platforms to find out.
A third option is 'The Alliance of Obito and Madara'. In this one, the author focuses on their combined power and how they could have ruled the ninja world together. It's full of action scenes and also has some deep emotional moments between the two characters.
In such a fanfiction, the story could take a very dark turn. Naruto's ideals of friendship and peace might be severely tested. He could be forced to question his own beliefs as Obito and Madara have very different outlooks. Maybe Naruto would try to change their minds, but it would be extremely difficult as they are both very set in their ways of achieving a new world order through more extreme means.
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.
One common theme is redemption. Since Obito has done a lot of bad things in the Naruto series, many fanfics focus on him trying to make up for his mistakes. Another theme is love, whether it's his love for Rin that drives his actions or new relationships he forms.
A different fanfiction could involve a magical experiment gone wrong that transports Harry Potter to the Naruto world where he meets Obito. Harry, with his knowledge of magic, and Obito, with his ninja skills, have to find a way back to their respective worlds. Along the way, they learn from each other's cultures and abilities. Harry could teach Obito about some basic spells, and Obito could show Harry some ninja techniques like how to move stealthily or use a kunai effectively.