Perhaps in the fanfic, an enemy targets Naruto's nervous system with a special jutsu. As a result, he starts experiencing strange sensations and visions. His friends then have to find a way to reverse the effects while Naruto battles against the mental and physical chaos.
Maybe the horns are a sign of a new power awakening within Naruto. He could initially be afraid of them and hide them, but as he discovers their potential, he learns to embrace this new aspect of himself and use it to protect the village in ways he couldn't before.
Maybe Naruto forms an army to explore a new and dangerous territory. He realizes that there are threats lurking in an uncharted land that could potentially harm the ninja world. So, he uses his charisma to assemble an army of brave and skilled ninjas. This army would be made up of different types of ninjas, like those with special bloodlines and those who are experts in stealth or combat. They would set out on an adventure, facing various challenges along the way.
One possible plotline could be Naruto discovering his connection to Madara later in his life. This revelation could send shockwaves through the ninja world. Maybe he'd face discrimination or extreme reverence because of it. Another could be that Naruto has some latent powers inherited from Madara that start to emerge and he has to learn to control them while also dealing with the political implications of being related to such a controversial figure.
A possible plotline could be that Naruto's mother returns from the dead in some way. This could create a huge stir in the ninja world. Naruto would have to deal with his new - found family situation while also facing the challenges that come with it. There could be enemies who target his mother because of her connection to Naruto or some secrets she holds. And Naruto would have to learn to balance his relationship with his mother and his duties as a ninja.
One possible plotline could be that Naruto's brother has been living in secret all this time. Maybe he was sent away for his own safety when they were young. He could return to the village and at first Naruto is suspicious, but as they get to know each other, they form a strong bond and fight together against the common enemies of the village.
One possible plotline could be that Naruto's sister is overly protective of him. She might get jealous when Naruto spends time with his friends, especially female friends. For example, when Naruto goes on a mission with Sakura, his sister could be sulking at home, worried that Sakura might take Naruto away from her in some way.
In a fanfic where Naruto has to go through puberty again, the story could focus on his social life. Naruto was always an outcast as a child, but now with puberty, he might have a chance to reinvent himself. He could become more popular among his peers, but also face new rivalries. For instance, some of the other boys in the village might be jealous of his newfound confidence or the attention he gets from the girls. This could lead to some interesting battles and competitions, not just physical ones but also in terms of popularity and respect within the village.
In a fanfic, Naruto could inherit the Sharingan from a long - lost relative. This relative could be an Uchiha who fell in love with an Uzumaki long ago. With the Sharingan, Naruto gains the ability to predict his opponents' moves more accurately. He uses this new power in combination with his Rasengan to create new and powerful jutsus, and he also has to figure out how to control the Sharingan's curse, which comes with its own set of challenges.
Maybe Naruto's bat wings are a gift from a mysterious being. This gives him an edge in his ninja missions. He might start exploring caves and other dark places that normal ninjas can't reach easily with his new ability to fly. His friends might be a bit jealous at first but then see how useful it can be for the team as a whole.
One possible plotline could be that the older brother was thought to be dead but actually survived and returns to protect Naruto from the shadows. He might have some special powers or knowledge that he uses to keep Naruto safe without revealing his identity at first.