His relationship with his teachers could change too. Kakashi might have to develop new training methods for Naruto to master this kekkei genkai. Iruka would be very supportive as always, but also a bit worried that Naruto might attract more dangerous enemies with this new power. And with the other ninja villages, they might view Naruto with more caution or respect depending on how powerful his kekkei genkai is.
His enemies would surely react differently. Some might be more afraid of him and try to avoid direct confrontation. Others, like the more powerful villains, would see it as a new challenge and would be eager to test themselves against Naruto's newfound power. His new kekkei genkai could also attract the attention of other powerful ninjas who might want to form alliances with him or steal his power for themselves.
His relationship with Sasuke might become more competitive. If Naruto awakens a powerful kekkei genkai, Sasuke, who is always striving to be stronger, would see Naruto as an even greater rival. This could lead to more intense training sessions between them and also some tension in their friendship.
Kekkei genkai can make a character stand out. For instance, if a character has a rare and powerful kekkei genkai, others in the harem might be initially attracted out of admiration for their power. It can be a starting point for relationships.
It might isolate him. If his Kekkei Genkai is very powerful and different, others could be afraid of him. For example, if he has the power to see into people's souls, it could make people uncomfortable and they might avoid him.
In fanfiction, if the Uzumaki's kekkei genkai is a sealing - based one, clans with valuable secrets or jutsu might be cautious around them. They might be worried that the Uzumaki could seal away their important techniques. On the other hand, clans with a need for better sealing might approach the Uzumaki for help, leading to various types of relationships, from friendly cooperation to tense negotiations.
Well, it could be something like a fire - based kekkei genkai that allows Naruto to control blue - flame fire which is hotter than normal fire. This would give him an edge in battles and also a new look to his fighting style.
Well, in some fanfictions, Naruto might obtain all kekkei genkai through some sort of ancient and powerful jutsu. Maybe he discovers a hidden scroll or meets a mysterious sage who imparts this power to him.
The new Kekkei Genkai could make Naruto more empathetic. Since it's a gift from Kyuubi, he might start to understand the tailed - beasts better. He could use this new power to help other people in the village who are having trouble with their own powers or abilities. This would further his development as a hero in the village, not just a powerful ninja, but someone who uses his power for the good of others.
It could change his relationship with his enemies too. Enemies might be more hesitant to attack him, not knowing what the mouths on his hands can do. Some might be so freaked out that they avoid him altogether. His relationships with his sensei, like Jiraiya, would be interesting. Jiraiya would likely be excited to study this new phenomenon and help Naruto figure out how to use it to his advantage. And Naruto's new 'hand - mouths' could also bring him closer to some characters who are interested in the strange and unusual in the ninja world.
It would likely strengthen his relationship with Kakashi. Kakashi, being Naruto's teacher, would be intrigued by this new power and help Naruto train and master it. His respect for Naruto would grow as he sees Naruto handle such a powerful and unique summon. With Sasuke, it could be a source of both envy and a reason for him to re - evaluate Naruto. Sasuke might initially be jealous of Naruto's new power but later realize that they need to work together, especially if the dragon summon is crucial in fighting a common enemy. As for his friends like Shikamaru and Choji, they would be in awe of Naruto's dragon and it would make them more eager to fight alongside him, seeing him as an even greater asset in battles.
With his friends like Sakura and Kakashi, they might be initially confused but then supportive. Sakura could be worried that Naruto is getting involved in something dangerous related to the moon, but also trust that he knows what he's doing. Kakashi, on the other hand, would likely be more intrigued and offer his wisdom and guidance as Naruto explores this new aspect of his life.