The black chakra could make other characters view Naruto with suspicion. His friends might be worried that this new power is corrupting him, which could strain their relationships. For instance, Sasuke might see it as a sign that Naruto is becoming more like the enemies they've fought.
In the fanfic, Naruto's black chakra could also attract some new characters who are either drawn to its power or who know something about it. This could introduce new relationships for Naruto. Some might want to help him harness it for good, while others might want to use it for their own evil purposes, and all these new interactions would have a significant impact on his existing relationships as well.
Some characters might be afraid of Naruto if he has black chakra. For example, his friends like Sakura and Kakashi could be initially cautious around him. They might not trust this new, unknown aspect of his power. Sakura might worry that the black chakra could harm Naruto himself, while Kakashi would be on high alert to make sure Naruto doesn't lose control.
Enemies would definitely be more cautious around Naruto. Those who once underestimated him would now fear his golden chakra. This could lead to some enemies trying to find weaknesses in it. Meanwhile, Naruto's new power might also attract the attention of mysterious characters who want to guide him in using it, which could cause some friction with his existing relationships as he has to decide who to trust.
Naruto's chakra mastery affects his relationships in multiple ways. In his friendship with Shikamaru, his chakra control allows him to keep up with Shikamaru's strategic plans during battles. This makes their teamwork seamless. With Hinata, Naruto's powerful chakra makes him more of a hero in her eyes. His chakra also gives him the ability to sense when Hinata is in danger and come to her rescue. Among the villagers, his chakra mastery earns him more respect, which changes the way they interact with him from being skeptical to being admiring.
His relationship with Sasuke would be greatly affected. Initially, Sasuke might not care much as he's so focused on his own path. But later, he might realize that Naruto was an important part of the team dynamic. Without Naruto, Sasuke may find that he misses the competition and the unique bond they had, which could lead to some self - reflection for him.
Naruto's dense chakra could make his friends either jealous or in awe. If he can do things with his chakra that others can't, some might envy his power. But his true friends like Sasuke and Sakura would be in awe and see it as a way to strengthen their team. For example, Sasuke might see Naruto's dense chakra as a new challenge to keep up with, which could improve their friendly rivalry.
On the other hand, it could also strengthen his relationships with some characters. For instance, Kakashi, as his teacher, could be more proud of Naruto's growth in harnessing such a powerful force. And Naruto might also become a more respected figure among the younger ninja, who look up to him for his new - found power.
His relationships with his friends would likely be severely strained. For instance, Sakura and Sasuke, who know Naruto as a kind - hearted person, would be horrified and confused. They might try to find a way to cure him or bring him back to his normal self.
If Naruto has a physical disability like a broken arm that doesn't heal properly in fanfiction, his friends like Sasuke and Sakura would need to step in and help him more. Sasuke might be more protective, which could change their dynamic from a competitive one to a more collaborative one. Sakura could use her medical skills to try and find a way to heal him, which would bring them closer. His relationship with his teachers, like Kakashi, would also change as they'd have to adjust their training methods.
It could strain his relationships. His friends might be initially scared of him. For example, Sakura might be hesitant to be near him, fearing that the dark chakra could make him lose control and hurt her.
His relationship with his sensei, like Kakashi, could become more complex. Kakashi would feel guilty for not being able to protect Naruto from the experiments. And Naruto might start to question Kakashi's ability to keep him safe. This could lead to a strain in their relationship at first, but later they could grow closer as Kakashi helps Naruto recover from the trauma of the experiments.