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.
His Kekkei Genkai could also affect his romantic relationships. If it has some sort of dangerous side - like a power that can go out of control - his love interest might be hesitant to get closer. However, if she is also a strong - willed shinobi, she could see it as a challenge and be drawn to him even more, wanting to help him master his ability and overcome any potential threats it poses.
On the other hand, it could attract certain people. Those who are interested in power or unique abilities might want to befriend him. For instance, some shinobi might see his Kekkei Genkai as a way to gain an advantage in the ninja world and form alliances with him.
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.
Another possibility is that his Kekkei Genkai gives him the power of telepathy on a much larger scale. Not only can he communicate with others mentally, but he can also influence their thoughts and actions to a certain extent. This could add a whole new layer of intrigue to the story, especially in political or strategic situations where mind control or persuasion could be crucial.
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.
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, 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.
Kekkei genkai can be a major driving force in the plot of Naruto fanfic. If a character has a unique kekkei genkai, it can make them a target. For example, if a character has the ability to control rare elements, other villages or villains might try to capture them to use their power. This can lead to a chase or a battle to protect the character. It can also change the power dynamics in a fight. A powerful kekkei genkai can turn the tide of a battle, creating unexpected twists.
In fanfiction, it could be due to some special training. Maybe he meets a super powerful mentor who has knowledge of all kekkei genkai and teaches him the secrets. Or perhaps he discovers some ancient jutsu that unlocks this ability within him.
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.
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.