He may develop new abilities or a different fighting style as a result of losing his humanity. His connection with the Kyuubi could be enhanced in a way that is more primal. Instead of using the Kyuubi's power in a controlled and purposeful way like before, he might access it in a more instinctive and unpredictable manner, making him a much more dangerous and less predictable opponent.
His character would take a dark turn. He'd likely become more aggressive. Without his humanity, Naruto may not show mercy or compassion in battles.
Naruto's development could involve a struggle between his old self and the new, inhumane self. The presence of the female Kyuubi could act as a catalyst for this internal conflict. She might represent a different set of values that are in contrast to what Naruto once stood for. For instance, she could encourage him to be more self - centered and power - hungry, which goes against Naruto's original altruistic nature.
Other characters in the Naruto universe might also be affected. For example, his friends like Sakura and Kakashi would notice the change in Naruto. They might try to help him, but their attempts could be in vain because of the complex situation with the Fem Kyuubi involved. This would create new tensions and storylines as they struggle to deal with a Naruto who has lost his sanity and the mystery of the Fem Kyuubi's role in it.
Naruto's character might develop in terms of his power control. With Amaterasu in the mix, he has to learn to be more cautious as it's a very destructive force. The Fem Kyuubi could also teach him patience. For example, he may become more strategic in battles instead of just relying on brute force. He could also develop more emotional depth as he navigates the complex relationship with the Fem Kyuubi and the power of Amaterasu.
The fem Kyuubi might feel a sense of protectiveness. Seeing Naruto without his mask could make her realize how vulnerable he is. She may then use her powers to safeguard him from any potential threats that could take advantage of his exposed state.
At first, their relationship might be based on mutual need. Naruto, being the one who wants to right the wrong of her banishment, and the Fem Kyuubi, who may need someone to help her. As they spend more time together, they start to understand each other better. Naruto sees the Fem Kyuubi not just as a powerful being but as a sentient individual with feelings. The Fem Kyuubi, in turn, realizes that Naruto is different from the others who feared or hated her. This understanding gradually turns into a deeper emotional bond, which could develop into love over time.
He might become more withdrawn. Without his happiness, Naruto would lose his usual exuberance. He would probably start to isolate himself from others, as he no longer has that positive energy to share. For example, he might stop going to his favorite ramen place and avoid his friends.
In many fanfictions, Fem Naruto might show kindness towards the Kyuubi. This kindness could be something the Kyuubi has never experienced before. For example, instead of just seeing it as a source of power, Fem Naruto might try to understand the Kyuubi's past and pain. This could lead to the Kyuubi gradually opening up to her and them developing a deeper bond.
In this scenario, Naruto would experience a significant shift in his character. He would be forced to make tough decisions. For example, he would have to choose between the village's rules and his loyalty to the fem Kyuubi. This would make him more mature. His relationship with the fem Kyuubi would also bring out a more protective side of him. He would have to learn how to control the power she represents in a new way. Additionally, being outside the village would expose him to different cultures and ways of life, which would shape his beliefs and values. All these factors combined would transform Naruto into a very different kind of shinobi compared to the one we know in the original series.
Naruto would likely become more in tune with his Kitsune side. He might gain more confidence as he realizes the unique powers it gives him. His relationship with the Fem Kyuubi would also force him to be more empathetic and understanding, as he has to deal with her complex emotions.
Naruto's character often develops in terms of his emotional maturity. In a harem situation with a fem Kyuubi, he has to handle multiple relationships, which makes him more understanding and empathetic. He also might develop his leadership skills as he is sort of the center of this group. He'll learn to make decisions that benefit the whole 'harem' and not just himself.
The female Kyuubi might start with a relationship of distrust towards Naruto. After all, the Kyuubi has a long history of being feared and hunted. But as Naruto shows her kindness and understanding, she could gradually warm up to him. The female Juubi, being a more mysterious and powerful being, might be initially indifferent to Naruto. However, when she sees his determination and the good in him, she starts to respect him. Their relationships would develop through shared battles and experiences, with Naruto constantly proving himself to be a worthy ally and friend.