Naruto may face several challenges. Firstly, understanding the nature of the jutsu itself. The Hidden Mist Jutsu is not just about creating mist but also about using it to one's advantage in combat and stealth. He would need to study how to move within the mist without giving away his position. Secondly, he might face opposition from some in the village. Since this is a jutsu associated with the Mist Village, there could be those who are skeptical or even against him learning it.
One challenge could be mastering the chakra control required. The Hidden Mist Jutsu demands a precise amount of chakra to create a thick and effective mist. Naruto has had issues with chakra control in the past, so this would be a hurdle. Another challenge might be adapting his fighting style. He's used to more straightforward and aggressive attacks, and the stealthy nature of the Hidden Mist Jutsu would require a different approach.
Well, for Naruto in this fanfiction, a major challenge would be dealing with the recoil of Raikiri. Since it's a powerful jutsu, it likely has a significant recoil effect on the user. Naruto would need to learn how to manage that so he doesn't get hurt every time he uses it. Also, in the world of fanfiction, there could be other ninja who don't want Naruto to learn Raikiri. They might try to sabotage his training, which would be an external challenge he has to face. And let's not forget that Naruto has his own unique fighting style. He would need to find a way to integrate Raikiri into his existing style without losing his edge in combat.
One challenge could be the complexity of the jutsu itself. His father's jutsu might be very advanced and require a high level of chakra control that Naruto doesn't initially have.
One challenge could be the physical strain. The Harashin technique might require a different kind of chakra control and physical movement than what Naruto is used to. For example, it could demand more precise and rapid movements, which might be difficult for Naruto at first.
One challenge Naruto might face is Gaara's past traumas. Gaara has been through a lot of pain and isolation, which has made him distrustful. It would be difficult for Naruto to break through those barriers and get Gaara to open up. Another challenge could be the political situation. Suna and Konoha have had their differences in the past, and some in Suna might not be happy with Naruto's influence on Gaara. Naruto would have to deal with any potential political unrest or opposition from those who don't trust Konoha.
Naruto would likely struggle with Hinata's shyness. He is a very outgoing person, and suddenly being in a body that is naturally more reserved could be difficult. For instance, when interacting with other characters, he might accidentally come across as too forward or too quiet, which could lead to misunderstandings. Also, Naruto would have to deal with Hinata's personal relationships. Her friends and family know her in a certain way, and any changes in behavior due to Naruto's possession could cause concern or confusion among them.
Well, it could be portrayed as a jutsu with a mind of its own. For example, in some fanfics, the mist seems to be able to guide the user or even act independently to some extent.
One great 'Naruto Hidden Mist Jutsu' fanfiction is 'Mist's New Hope'. It focuses on a young shinobi who discovers a new way to use the Hidden Mist Jutsu in a more strategic and powerful way. It has some really cool fight scenes.
One challenge could be controlling the space - time aspect of Kamui. It's a very complex jutsu, and Naruto, who is used to more straightforward chakra - based attacks, might struggle to understand the intricacies of warping space and time.
One challenge could be the physical differences in his body compared to those who traditionally learn the Black Leg Style. Naruto's own ninja training has focused on different aspects like chakra control for his shadow clones, and adjusting to the more physical and acrobatic demands of the Black Leg Style might be tough.
Also, he may face opposition from others in the village. Some might think that Naruto is straying from his traditional ninja path by learning a sword style. They could try to discourage him or not support his training, which would be an additional hurdle for him to overcome as he tries to master this new skill.