It could have a mixed impact. Some characters may be intimidated. Naruto's usual friendly and boisterous nature is replaced with Zabuza - like traits. Those who were close to him, like Iruka, would be worried. They would try to reach out to him to understand why he has changed. His relationships with the villagers could also take a hit. Since Zabuza was an outsider and a bit of a threat in their eyes, Naruto acting like him might make the villagers less trusting. However, some of the more battle - hungry ninjas in the village might see him as a stronger and more interesting ally now.
Well, in such fanfictions, Naruto's stupidity might make some characters more protective of him. For example, Sasuke could be more annoyed at first but gradually become more concerned as he realizes Naruto's good heart beneath the 'stupid' actions. And Sakura might scold him more often, but still care for him in a sisterly way. It can create some interesting dynamics in their friendships.
His relationship with Dumbledore could become more complex. Dumbledore knew Sirius well, and if Harry starts emulating Sirius' more impulsive side, Dumbledore might have to be more hands - on in guiding Harry. On the other hand, among the other Gryffindors, Harry could become a sort of leader figure. Since Sirius was a popular and respected Gryffindor in his time, Harry acting like him could inspire his housemates and lead to more group activities and a stronger sense of unity within Gryffindor.
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.
His soldier - like behavior could initially cause some distance. His friends might be a bit intimidated because soldiers are often associated with strict discipline. However, as they get used to it, they would realize that Naruto is still the same person deep down. He just has a new sense of duty that can actually help protect them all in the long run.
When it comes to his friends like Shikamaru and Choji, Naruto might distance himself from them. Zabuza is a loner, and being raised by him, Naruto could start to prefer solitude. He might not value the group dynamic as much as he does in the original story and instead focus on his own strength and survival skills.
It could improve his relationship with Sasuke. Since Chidori was Sasuke's signature move for a long time, Naruto learning it might show Sasuke that Naruto respects his skills and is willing to incorporate them into his own fighting style. This could lead to a more positive and equal relationship between them. Also, Kakashi might see Naruto in a new light. He trained Sasuke in Chidori, and seeing Naruto master it too could make him realize Naruto's determination and growth even more.
With his friends in Konoha, they would be worried and perhaps a bit afraid. They know Orochimaru's reputation as a villain. Naruto's friends like Shikamaru might start to keep a closer eye on him, which Naruto could resent. He would feel like they don't trust him anymore, and this could strain their friendships.
Well, it might make his relationships more intense. His Saiyan nature often means he's more aggressive and competitive. So, his friends like Krillin might be a bit more cautious around him. And his enemies would feel even more threatened. It could also lead to some friction with Vegeta as they both have Saiyan pride and might butt heads more often.
Well, if Gohan starts acting like Vegeta, it might strain his relationship with Piccolo at first. Piccolo is used to the more mild - mannered Gohan. But over time, Piccolo might come to respect this new assertive side of Gohan. With his father Goku, Gohan's new Vegeta - like behavior could create some friendly rivalry. Goku might be a bit surprised but also excited to see this new side of his son.
Some of his friends might be worried at first. They know Zabuza was a dangerous enemy before. But Naruto could convince them that he'll use the sword for good.