His relationship with Sasuke could change significantly. With the new power from the merge, Naruto might be seen as more of a threat by Sasuke, or Sasuke could be jealous of Naruto's newfound strength. On the other hand, it could also lead to Sasuke respecting Naruto more and seeing him as an equal in a different way.
Naruto's friends like Sakura and Kakashi might view him differently. They could be in awe of his power, but also a bit worried. Sakura might be concerned about Naruto losing himself in the Kyuubi's power. Kakashi, on the other hand, would likely try to guide Naruto to use this power responsibly, which could strengthen their teacher - student relationship.
In terms of his relationship with the villagers, they could be both fearful and hopeful. Fearful because they remember the Kyuubi as a destructive force, but hopeful that Naruto can use this power to protect them. Naruto would have to work hard to gain their trust again, which could be a complex and interesting part of the fanfiction.
Naruto's character becomes more complex. He gains a new level of confidence due to the power of the merge. He also becomes more aware of his own strength and how to use it responsibly.
The symbiote could make Naruto's relationships more complicated. For her friends, they might be initially scared or distrustful of the new - looking Naruto with the symbiote. For example, Sasuke might see her as a threat now. But as they learn that the symbiote is actually helping Naruto control the Kyuubi, they might slowly accept it.
When the Kyuubi possesses Naruto, his friends' trust in him is tested. Some, like Shikamaru, might be more cautious and try to keep an eye on Naruto to make sure he doesn't go out of control. Others, like Choji, might be more sympathetic and try to offer Naruto support. This possession changes the dynamics. Naruto might feel isolated as his friends struggle to understand what's going on with him, and it takes time for them to rebuild their normal relationships.
The Kyuubi suit might make her relationships more complex. Her friends could be both in awe and a bit scared of her new power. For example, Sasuke might be initially hesitant to approach her as he's not sure how to deal with the Kyuubi's influence. But over time, as he sees that she's still the same Naruto at heart, their relationship could strengthen.
When Naruto releases the Kyuubi in the fanfic, it might change his relationship with his sensei, Kakashi. Kakashi would be on high alert, ready to step in if Naruto loses control. At the same time, he would be guiding Naruto on how to better manage the Kyuubi's power. This could bring them closer as Naruto learns from Kakashi's experience. And Naruto's relationship with the other ninja in the village would also shift. Some would look up to him more as a powerful force to protect them, while others might be jealous of his new - found strength.
With Sasuke, it could go either way. Sasuke might see Naruto as an even greater rival now that he has the Kyuubi's power. Or, he could respect Naruto more for being able to harness such a great power. But overall, it would add a new dynamic to their complex relationship.
It could make her relationship with Sasuke more complex. Sasuke might be both intrigued and a bit jealous of her newfound power from the symbiosis. He could see her as a greater rival or, on the other hand, a potential ally he needs to keep close.
Well, it could make some characters fear him. For example, those who don't understand the nature of his succession might be wary. But his friends, like Sasuke, might see it as just another aspect of Naruto. They've seen his determination before, and this new status could be seen as an extension of his power and the challenges he has to face.
His relationships would become more complex. The villagers who once hated him for having the Kyuubi inside him might now be even more terrified as he has its soul. However, Naruto's friends like Shikamaru would likely see this as an opportunity for Naruto to grow even stronger. They would try to help him harness this new power while also making sure he doesn't lose himself to the Kyuubi's wild nature. This new situation would test all of his relationships.
In fanfiction, the Naruto - Kyuubi pairing can greatly expand the power dynamics. For example, they might be able to defeat stronger enemies together more easily. It can also change the relationships Naruto has with other characters. If he has a closer bond with the Kyuubi, some characters might be more in awe or more fearful of him.