He would become more cynical. Orochimaru's influence would make Naruto question the values he once held dear in the village. His appearance might also change, with a darker look in his eyes and a more menacing aura.
Naruto's personality would take a significant turn. He'd be more distrustful of others, having been exposed to Orochimaru's world of manipulation. His sense of humor might disappear as he gets caught up in Orochimaru's dark plans. His relationships would also be affected. His friends would be confused and concerned about his new allegiance, and Naruto would have to deal with their reactions while still being loyal to Orochimaru in the fanfic, at least initially.
Naruto would likely become more secretive. Working for Orochimaru means being involved in a lot of underhanded activities. He would have to hide things from his friends. His fighting style might also change as he incorporates Orochimaru's techniques. He could become more ruthless in battle, less concerned about the well - being of his opponents as he focuses on achieving Orochimaru's goals.
Naruto would likely be more cunning. Since Orochimaru is known for his devious ways, Naruto might inherit some of that. He could be more calculating in battles rather than just relying on brute force. However, he would still have his core of kindness. So, it would be an interesting mix of Orochimaru's slyness and Naruto's big - heartedness.
Naruto's morality could be somewhat skewed. Orochimaru has a very different view on right and wrong compared to Naruto. So, Naruto might start to question some of his previous beliefs. For example, he might be more willing to use dangerous or forbidden jutsus if it means achieving his goals. He'd also probably be more distrustful of others, as Orochimaru always has ulterior motives. This would be a big change from the Naruto who was always so quick to trust and befriend people.
He'd be more cynical. Orochimaru's ways would make Naruto question the goodness in people.
Well, Naruto's character might become more morally ambiguous at first. Since Orochimaru is a rather shady character, Naruto could start to question some of his previous beliefs. He might become more power - hungry, but also more self - reliant in a way as he tries to master the new power. However, he could also struggle with the darker aspects of Orochimaru's power, like having to use some underhanded tactics.
Maybe in this fanfic, Naruto has been influenced by some dark force or a traumatic event that makes him turn to Orochimaru. Orochimaru, seeing Naruto's potential, convinces him to work together. Naruto's tasks could involve helping Orochimaru in his experiments. However, as time passes, Naruto realizes the true evil nature of Orochimaru and has to struggle between the loyalty he feels due to the power he's gained and his own moral compass.
Naruto would likely become more secretive. Since Orochimaru is a very private and often devious character, Naruto might pick up some of those traits. He would probably keep things from his friends more often.
Naruto would likely become more secretive. Since Orochimaru's training methods are often not in line with Konoha's values, Naruto would have to hide what he's learning. He might also become more distrustful of others as Orochimaru could instill in him the idea that everyone is out to get him for his newfound power.
In some fanfics, Naruto might use his new and powerful jutsu that he has mastered over time. Maybe he combines his Sage Mode with the power of the Nine - Tails in a unique way that Orochimaru can't counter. For example, he could use the Nine - Tails' chakra to enhance the range and power of his Sage Mode attacks, and then catch Orochimaru off - guard.
His character could develop in a darker direction. The torture and manipulation from Orochimaru's experiments could make him question his values. However, it could also strengthen his resolve to protect his friends and the village. He may start to see the world in a more complex way, understanding that there are greater evils out there. And his newfound powers from the experiments could give him a sense of responsibility that he didn't have before.
Naruto could develop a new sense of determination. He might be determined to not let Orochimaru's experiments define him. Instead, he could use what has happened as a motivation to become stronger in his own way. He may also start to study more about the type of experiments Orochimaru was doing, not to replicate them, but to find ways to counter any future threats related to that kind of science.