His relationship with his friends would likely change. He might become more distant at first as he focuses on his training with the female shinigami. But in the long run, his new powers and insights could make him a better protector of his friends. For example, he could use his newfound skills to rescue them from more dangerous situations.
In such a fanfiction scenario, Naruto might gain some really unique powers. The Shinigami could teach him about different forms of spiritual energy which could enhance his already formidable chakra. Maybe he'd learn to manipulate souls or gain a new level of perception.
Perhaps the female shinigami trains Naruto to have a better understanding of life and death. In the Naruto world, death is a significant concept, and with the shinigami's training, Naruto could become more in tune with the cycle of life and death. This might lead to him being able to communicate with the spirits of the dead, getting advice from past Hokages or his parents in a more profound way.
In a fanfic where Naruto is trained by the Shinigami, Naruto would face a whole new set of challenges. The training would be tough as the Shinigami's methods are likely to be very different from what he has experienced before. He might have to endure tests that involve facing his inner demons or dealing with the power of death directly. This could lead to a significant character development for Naruto. He would not only become stronger physically but also mentally, as he grapples with the complex concepts associated with the Shinigami's realm.
Well, Naruto being trained by the Shinigami in a fanfic would be a wild ride. Naruto's character would likely change a bit. He'd be exposed to the Shinigami's rather dark and mysterious world. This could make him more solemn at times. In terms of his abilities, he could gain the power to temporarily 'borrow' the strength of deceased ninjas. He might also develop a new kind of Rasengan that has a spiritual component, something that can not only damage the body but also affect the soul of his enemies.
Perhaps it could be a female version of an existing kami from Naruto lore. For instance, a female counterpart of the Sage of Six Paths. She would have vast knowledge and power, and her training of Naruto would be a way to pass on that ancient wisdom and strength.
Yes, there are likely fanfictions with such a concept. The idea of a 'godlike' Naruto trained by the female Kyuubi is an interesting and popular concept in the Naruto fanfiction community. It allows for unique storylines and character developments.
Naruto's chakra - based powers and the fem shinigami's reiatsu - based powers could create some unique combinations. For example, Naruto could use his shadow clones to help the fem shinigami in battle while she uses her zanpakuto to enhance the strength of the clones.
His powers would likely include some form of soul manipulation. He might be able to sense the souls of others more acutely, which could give him an edge in battle by predicting his opponents' moves.
The training by the fem Kyuubi could also change Naruto's view of the world. He might start to see the tailed beasts in a new light, not just as powerful and dangerous entities but as beings with their own personalities and stories. This could potentially lead to him trying to bridge the gap between humans and tailed beasts in the fanfiction world.