When Naruto turns into the Nine - Tailed Fox in fanfiction, it could have a huge impact on his relationship with his teacher, Kakashi. Kakashi would need to figure out new ways to train Naruto to control this power. And Naruto might start to feel a bit isolated from his friends at first, thinking they see him only as a monster now. However, over time, his true friends would come to accept him again, strengthening their bonds in a new way.
It could make his friends more cautious around him. For example, Sakura might be a bit more hesitant to get close, fearing the power of the Nine - Tailed Fox. But at the same time, some like Sasuke might see it as an opportunity to become stronger by sparring with Naruto in this new form.
His relationship with the villagers could become more complex. Some might see him as a greater threat, while others who have come to know Naruto as a hero might be more accepting. His transformation could also lead to new alliances as some might want to use his power for their own purposes, which Naruto would have to navigate carefully to protect his relationships.
It would greatly affect his relationship with Sakura. She might be scared at first, seeing Naruto with such a powerful and dangerous force. But if Naruto manages to control it, she could grow to respect him even more. With Sasuke, it could be a different story. Sasuke might see Naruto's new - found power as a challenge or a threat, which could either drive them further apart or lead to a more intense rivalry where they both strive to become stronger in different ways.
Well, in some fanfictions, Naruto might start his journey after a particularly intense battle where he realizes the full potential of the Nine - Tailed Fox's power within him. It could be a fight against a strong enemy that makes him understand he needs to control the fox's power to protect his friends and the village.
It can completely turn the plot around. If the story was about Naruto being in a tough situation against a powerful enemy, summoning the Nine - Tailed Fox could be the solution to that problem. It could be like a deus ex machina moment, but also very exciting for the readers.
There are fanfictions where the Nine - Tailed Fox has a split personality. One side is the fierce and powerful beast, and the other is a more gentle and understanding entity. Naruto has to deal with both sides, which creates a very complex and different kind of relationship compared to the original series. This can lead to some really interesting character development for Naruto as he tries to balance and understand this unique relationship.
His character development would be more complex. He'd have to deal with the dual nature of being both Naruto and the Nine - Tailed Fox. He might become more aggressive at times due to the fox's influence, but also gain new insights and powers that could shape him into a more powerful and wiser ninja.
He becomes more aggressive. The nine - tailed fox's nature seeps into Naruto, so he's quicker to anger and more likely to lash out. For instance, he might not think as rationally as he usually does when making decisions in battle or in dealing with his friends.
One interesting plot could be Naruto fully transforming into the Nine - Tailed Fox during a battle against a powerful enemy. His friends are initially shocked but then try to find a way to bring him back to his senses.
One possible plot twist could be that Naruto loses control over his transformation into the Nine - Tailed Fox in a completely unexpected situation. Maybe during a friendly spar with his friends, and this causes them to fear him in a new way. It would add a whole new layer of drama to their relationships.
She could change the power dynamics. In the Naruto universe, power is often associated with male characters. A female Naruto with the Ten - Tailed Fox would break that mold. Her presence might inspire other female characters to strive for greater power. For example, female ninjas could see her as a role model and start to train harder to gain similar levels of power.