Zabuza could be portrayed as more of a mentor figure. Instead of just being a ruthless assassin, he could be shown guiding Naruto in some aspects of combat or strategy. Maybe he survived his encounter with Kakashi and had a change of heart, and now he imparts his knowledge to Naruto who is now a sensei himself.
Zabuza could also be portrayed as a symbol of hope in the fanfiction. Suppose Naruto's students are in a difficult situation where they feel like giving up. Naruto could tell them the story of Zabuza, how he overcame his own hardships in the Hidden Mist village, and how he was able to find purpose even in his dark life. This would show Zabuza in a more positive and inspiring light compared to his initial portrayal.
Zabuza could be quite cold to Naruto at the beginning. He's not exactly the warm - and - fuzzy type. But when Naruto shows his skills and tells his story of being banished unjustly, Zabuza might empathize on some level. He might not show it openly, but he could start to protect Naruto in his own way, perhaps because he sees a bit of his younger self in Naruto who was also wronged by the ninja system.
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.
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.
Well, Naruto is a very impressionable character. His idolization of Zabuza might make him more open to using unorthodox or morally grey techniques. He could start to question the black - and - white view of good and evil that he initially had. Maybe he would see the value in Zabuza's loyalty to Haku, which could in turn strengthen Naruto's own bonds with his friends.
A minor character like a blacksmith's apprentice could find Zabuza's sword. Instead of using it for fighting, they study it closely. They discover a unique metal alloy in the sword that they use to create new and improved weapons for their village. This not only changes their own fate as they become a renowned blacksmith, but also the fate of the village as they now have better weapons to defend themselves.
One idea could be that Naruto, as a sensei, takes on a student who has a similar past to Zabuza. He uses his knowledge of Zabuza's story to teach the student about redemption. For example, Naruto could tell the student how Zabuza was once a feared assassin but had a side that was capable of love and loyalty, as seen with Haku.
If Zabuza found Naruto, it could make Naruto more independent. Zabuza is a loner, and Naruto might pick up on some of his self - reliance. Naruto may also become more in tune with his darker emotions. Zabuza has a lot of anger and pain inside him, and being around him could force Naruto to confront his own inner demons. This would add depth to Naruto's character, as he would have to learn to control and use these emotions in a positive way, rather than just relying on his positive - thinking - only attitude all the time.
Naruto's character would likely become more hardened. Zabuza is a cold - blooded killer, and being around him would expose Naruto to a different set of values. Naruto might become more reserved and calculating in his actions.
Well, it could be due to some sort of mind - control jutsu. Maybe Zabuza uses a special technique that he learned in the Hidden Mist Village to make Naruto do his bidding.