The relationship with villages that have historical grudges against Kumo could be a bit rocky at first. They might think Naruto is getting too close to Kumo. However, as Naruto continues to uphold his values and show that the rescue was a matter of basic humanity and not a political move, other villages could come to respect his stance and might even be more open to forging new relationships with both Konoha and Kumo.
It could improve his relationship with Kumo significantly. Naruto would be seen as someone who has a connection with Kumo now. Other villages might view this with a bit of suspicion at first, but Naruto's positive influence could lead to better overall relations. For example, villages that have had tense relations with Kumo might see Naruto as a bridge and be more open to communication.
This rescue could lead to a more diplomatic Naruto. He might start to advocate for closer cooperation between Konoha and Kumo in particular. This could also make other villages more eager to ally with Konoha, seeing that Naruto is able to build such strong ties with a village that was once considered a rival. He would be seen as a unifying force in the ninja world.
One way could be a stealth mission. Shikamaru, with his high intelligence, could plan a strategy to infiltrate Kumo's hideout undetected. He could gather a small team of skilled ninja like Neji (if he were still alive in the fanfiction), Rock Lee, and Ino for mind - reading and communication. Then they could free Naruto and Hinata and escape before Kumo realizes what's happening.
Well, with his teachers, like Iruka. Iruka might be more hesitant in approaching Naruto at first because of his connection to the Kyuubi. But as he realizes that Naruto is still the same kind - hearted boy, he would become a stronger supporter. As for Kakashi, he could see Naruto as a more complex case. He would need to train Naruto not only in normal ninja skills but also in controlling his Kyuubi - born powers. This would create a different dynamic in their relationship compared to the original story. Naruto's peers in the village might also either shun him more or be in awe of his power, depending on their personalities.
If Gaara and Naruto are brothers, it could lead to a much closer alliance between Suna and Konoha. The two villages might start sharing more resources, like ninja training techniques. For example, Konoha could learn more about sand - based jutsu from Suna, and Suna could benefit from Konoha's more diverse range of ninja skills.
If Naruto and Mei had a baby, the relationship between Konoha and Kirigakure would likely become much closer. The baby would be a symbol of unity between the two villages. There would probably be more trade and cultural exchanges. Konoha might share some of its unique ninja training methods with Kirigakure, and vice versa. The two villages could also form a stronger alliance in the face of common threats, as they would now have a family - like bond through the baby.
In this fanfiction scenario, Naruto being Mito's brother would likely impact the political landscape too. The Uzumaki clan has always had an important role, and with this new relationship, Naruto could have more influence in diplomatic matters. Maybe he would have been more involved in the affairs of the Hidden Leaf earlier. Also, his relationship with the other clans, especially those related to the tailed beasts, might be different. For example, his connection with the Uchiha clan could be altered as he has this new Uzumaki - related status.
In the fanfiction, Naruto's emotionless mask might make Sasuke feel like he's lost his rival. Naruto's lack of emotional response could cause Sasuke to question if Naruto still cares about their bond. Sasuke might start to distance himself, thinking that Naruto has changed too much. However, as the story progresses, Sasuke could realize that the mask is just a facade and they could start to repair their relationship.
In this fanfiction, their relationship becomes more of a partnership. Instead of Naruto just using the Kyuubi's power, they work together as brothers. Naruto might start to understand the Kyuubi's feelings and motives better.
Well, it might make Naruto more withdrawn from characters who are close to Kushina. For example, if Minato is still alive in the fanfiction, Naruto's fear of Kushina could cause him to be less open with his father as well, since Minato was Kushina's husband. He might be worried that any information he shares with Minato could get back to Kushina.
His personality might be more rough around the edges. Kumo has a tougher environment, so he'd likely be more assertive.
His relationship with Hinata could change. She might be in awe of Naruto's new connection to such an ancient and powerful being. Naruto could also be more protective of her, fearing that his new enemies might target her to get to him. With his friends like Shikamaru and Kiba, they might look at Naruto in a different light, seeing him as even more of a mystery and a source of great power. They could be both more cautious around him and more eager to help him in any new battles or challenges.