Perhaps Sakon and Ukon could develop a new jutsu together with Naruto. This would not only show their growth in terms of power but also in their ability to collaborate. Their relationship could transform from one of enmity to one of mutual respect and friendship as they master this new technique.
Sakon and Ukon could develop from being ruthless and self - centered to more empathetic characters. For example, Naruto's positive attitude might start to rub off on them, making them question their previous way of life.
Naruto himself could develop a better understanding of the darker side of the ninja world through his interactions with Sakon and Ukon. He might learn that not all enemies are born bad, but are often a product of their environment.
At first, Naruto might be a bit confused and scared about having this Genkai. But as he explores its abilities, his confidence would grow. He could use the unique powers of the Ukon Sakon Genkai to his advantage in battles, and this would make him a more formidable ninja. His relationships with his friends might also change. Some might be in awe of his new power, while others might worry about him. Naruto would have to work hard to assure them that he's still the same Naruto at heart.
One possible plot could be Naruto discovers he has the Ukon Sakon Genkai in a moment of extreme danger. He then has to quickly learn to control it. Maybe at first he struggles with the dark aspects of this power, but eventually he masters it and uses it to defeat a powerful enemy.
Another idea is a story set in an alternate universe where Sakon and Ukon are raised as ninjas in Konoha. Naruto befriends them early on, and they go through the ninja academy together. Their unique abilities would make for some interesting training scenarios and missions.
For Naruto, he could develop more understanding of the darker side of the ninja world through his interactions with Tayuya. Tayuya, on the other hand, might start to see the value of friendship and loyalty like Naruto has. For example, Naruto's unwavering belief in his friends could rub off on Tayuya, making her question her previous solitary and somewhat ruthless ways.
Anko might develop a softer side through her interactions with Naruto. She has a tough exterior due to her past, but Naruto's unwavering optimism and kindness could start to break down her walls. She could become more open and trusting towards others in general.
For Naruto, he might become more settled and focused on building a family life. He's used to being the wild, go - getting hero, but with Tenten, he learns the value of a quiet home life. Tenten, on the other hand, could become more confident in her role as a partner to Naruto. She may also develop more diplomatic skills as she has to deal with Naruto's high - profile status in the village.
Naruto could develop a deeper sense of protectiveness. He has protected the village many times, but now his focus is on protecting Mei and the baby. This could lead to him learning new jutsu specifically for their safety. Mei might experience a change in her leadership style. She may start to see the importance of family values in the Mist Village and try to incorporate that into her rule. As she goes through the pregnancy, she could also become more empathetic towards the women in her village who are also mothers or expecting mothers.
Naruto would likely become more solemn and responsible. He's no longer just a ninja protecting his village but a being in charge of an entire universe. His view on life and death would change drastically. He might also develop new abilities related to the creation and destruction of matter.
In this fanfiction, Naruto may develop his patience. Healing is a delicate process and requires time and precision. He would have to learn to be patient, which is a new trait for him. Lee could develop a new sense of humility. Being healed by Naruto, he realizes that he can't always be self - sufficient and that relying on others is not a sign of weakness. This could change his attitude towards teamwork and cooperation in future ninja missions.
One possible development for Naruto is that he begins to show signs of leadership. Even as a baby, he might gather the other village kids around him and lead them in some small play - adventures. For Kushina, she could develop a more nurturing side. She might start to think more about the well - being of the whole village because she realizes that Naruto will grow up in this environment. So, she could be involved in activities that improve the living conditions in the village, all because of her love for Naruto.