At first, the apprentice might see Naruto as an enemy or at least a nuisance. However, Naruto's determination and his ability to never give up could intrigue the apprentice. As they are forced to work together on various tasks, they would start to understand each other better. Naruto could learn about the apprentice's loyalty to Zabuza and the apprentice could learn about Naruto's loyalty to his friends and village. This mutual understanding would lead to a deeper relationship.
It could start with mutual respect. Naruto's mage powers might earn Zabuza's respect as he sees the potential in them for his own goals. Then, they could develop a friendship based on trust. For example, Naruto trusts Zabuza not to harm him despite his fearsome reputation, and Zabuza trusts Naruto to use his magic to their advantage. As time passes, this friendship could turn into deeper feelings. Maybe they have a moment of shared vulnerability, like when they're both injured and have to rely on each other for survival. This would lead to the development of a romantic relationship, making them mates.
In this fanfiction, Jiraiya could be more open with Naruto about his past mistakes and love life. This would make Naruto see Jiraiya in a different light and might inspire him to be more cautious in his own relationships. Also, Naruto could be more protective of Jiraiya, knowing all that his master has been through. They would support each other not just in ninja battles but also in personal matters.
At first, it might be a bit rocky. Naruto is used to his own way of doing things, and Tsunade is a strict teacher. But over time, they would grow to respect each other. Naruto would see Tsunade's wisdom, and Tsunade would see Naruto's determination.
Naruto's development would be a journey of self - discovery. As Orochimaru's apprentice, he would be exposed to different forms of power and knowledge. He might initially be disgusted by Orochimaru's methods but then realize that he can use some of it for good. His social skills would change too. He would be more adept at dealing with enemies and those with different motives. His sense of humor might even change, becoming darker to fit in with Orochimaru's crowd. But deep down, his core values of friendship and protecting the weak would still be there, just masked by his new persona as Orochimaru's apprentice.
Naruto's character would become more hardened. Zabuza's influence would make him less naive. He would be more calculating in battles and less likely to rush in without a plan. His view of the ninja world might also change. He could see the darker side of it more clearly.
If trained by Zabuza, Naruto would probably grow in terms of his combat intelligence. He'd learn to read his opponents better. His personality could become more stoic, as Zabuza is not one for excessive emotions. But Naruto would also bring some of his own warmth to Zabuza's cold - blooded training regime. He might try to humanize Zabuza and in the process, become a more complex character with a blend of Zabuza's ruthlessness and his own compassion.
His sense of strategy would improve. Zabuza is a tactical fighter, and Naruto would learn to plan better in battles.
His view of the ninja world might change. Anko has a different perspective compared to some of Naruto's other mentors. She has seen the darker side of the ninja world, especially with her connection to Orochimaru. Naruto, as her apprentice, would be exposed to this side more, which could make him more cautious and also more understanding of those who have strayed from the right path.
Their relationship could also develop romantically. Naruto's kind heart and his journey of growth could attract Yasaka. And Yasaka's elegance and wisdom might draw Naruto in. They could have moments of shared vulnerability, like when Naruto shares his past traumas with Yasaka, and she comforts him. This emotional connection could lead to a deeper romantic bond over time.
In the fanfic, Naruto and Xenovia's relationship could develop through mutual growth. Naruto could teach Xenovia about the power of friendship and never giving up, while Xenovia could introduce Naruto to different concepts from her world. Their relationship would not be without its challenges. There could be misunderstandings due to cultural differences. But through communication and a shared desire to protect those they care about, their love would blossom. They would become each other's support system, always there for one another in both good times and bad.