One idea could be that Naruto is sent on a mission to the Hidden Mist Village and gets separated from his team. He then has to adapt to the Mist Ninja ways to survive. He might learn their unique jutsu, like some water - based techniques, and form unexpected alliances with Mist Ninja who admire his determination.
Well, if Naruto becomes a Mist Ninja, the whole power dynamic in the Naruto world would change. For one, the Mist Village has its own set of unique jutsus and training methods. Naruto would be exposed to different forms of combat and ninja skills. This could also lead to different alliances. Since Naruto is a central figure, his shift to the Mist Village might make Konoha view the Mist Village in a new light, either as a threat or as a potential closer ally. And his relationships with characters like Sasuke and Sakura would be greatly affected. He might end up having new rivalries within the Mist Village itself.
If Naruto becomes a Mist Ninja in fanfiction, it would have a huge impact on the ninja world's politics. Konoha might see him as a traitor, or they could try to negotiate with the Hidden Mist for his return. The Hidden Mist, on the other hand, would gain a powerful ally in Naruto. This could change the balance of power between the villages. Naruto himself would be in a unique position to bridge the gap between the two villages, using his newfound knowledge of the Mist Ninja and his roots in Konoha to promote peace and understanding.
Naruto would face the challenge of loyalty. He has deep - rooted loyalty to Konoha, and now he has to transfer that loyalty to the Mist Village. This mental shift would be tough. He'd also face challenges in terms of training. The Mist Ninja training is different in terms of intensity and focus. He'd have to learn how to be more stealthy and less obvious in his actions, which is quite the opposite of his usual style. And he'd have to deal with the possibility of being used by the Mist Village for their own purposes against his will.
Well, in many such fanfics, Naruto might achieve it through intense training. He could focus on mastering new jutsus, like some super - rare or advanced ones. Also, he might gain a deeper understanding of the ninja way, perhaps by facing and overcoming some really tough moral dilemmas.
One common theme is redemption. Many stories feature mist ninjas who have made mistakes in the past and are seeking to make up for it. Another is the struggle for power within the Hidden Mist Village.
In a 'naruto becomes a rogue ninja fanfic', it could start with Naruto being ostracized by the village due to his growing power which some elders fear. They try to suppress him, and Naruto, feeling betrayed, decides to leave and become a rogue ninja. He then might go on a journey to find a new place where he can be accepted for who he is, and along the way, he could meet new allies and enemies alike. He may also develop new jutsu away from the traditional teachings of the village.
It could be a group of rogue ninja who have a vendetta against Naruto. They might see his new status as a rogue as an opportunity to take him down. Maybe they were once defeated by Naruto when he was in the village, and now they want revenge. Also, there could be some hidden shinobi clans within the village who oppose Naruto's new path and try to stop him for their own reasons, like protecting the village's reputation or their own power within the village.
One great naruto mist ninja fanfiction is 'The Mist's Hidden Hope'. It focuses on a young mist ninja's journey to prove himself in the Hidden Mist Village. Another one is 'Mist Ninja Redemption' which tells a story about a former rogue mist ninja trying to find his place back in the village.
There would be a power shift. Since Madara was extremely powerful, Naruto - as - Madara would be an almost unstoppable force. Other villages would have to either ally with Konoha (which would be a difficult decision considering the situation) or try to find a way to counter this new threat. This could lead to a new arms race among the ninja villages.