One idea could be that Kurama, with his powerful demon abilities, has a unique bond with psychic - type Pokemon like Alakazam. Maybe he uses his chakra control skills to communicate with them in ways normal trainers can't. He could start his Pokemon journey in a region filled with mysterious forests, similar to the ones he knew in his original world, and form a team of Pokemon that complement his own strengths.
One key element is empathy. Naruto has to be able to empathize with Kurama's situation. Kurama has been locked away for a long time and has a lot of pent - up anger. If Naruto can understand that and show that he cares, it helps build the friendship. Another is communication. They need to be able to talk to each other, which in fanfiction often involves Naruto learning to communicate with Kurama on a deeper level than just yelling commands at his chakra.
In a fanfiction where Naruto becomes a Pokemon Trainer, he would bring a whole new dynamic to the Pokemon world. Naruto is used to facing tough opponents in the ninja world, and he would apply that experience in the Pokemon battles. He would be fearless in exploring new areas to find rare Pokemon. His loud and energetic personality would attract a diverse range of Pokemon. His training methods might be unorthodox, but they would likely be effective. For instance, he could use his shadow clone jutsu to train multiple Pokemon at once, just like how he uses it for his own training in the ninja world.
In many fanfictions, Ash achieving the status of a Pokemon Master often involves him having extraordinary battles. He might defeat powerful legendary Pokemon that no one has ever tamed before. His Pikachu could evolve into a more powerful form, which gives him an edge in battles. Also, his bond with all his Pokemon, not just Pikachu, becomes so strong that they can execute complex strategies without any communication barriers.
Kurama would likely become more empathetic. As a trainer, he'd need to understand his Pokemon's feelings to train them effectively. For example, if he has a timid Squirtle, he'd have to be patient and gentle, which could soften his usually tough demon - like personality.
Well, in such a fanfiction, Ash might experience the life of a Pokemon in a very different way. He could understand their thoughts and feelings more deeply. Maybe he'd have to learn how to use Pokemon moves in his new form, which would be a really strange and exciting adventure for him.
It could be a powerful and evil Pokemon trainer who wants to capture Ash in his new Pokemon form. This trainer might be after Ash because he believes that a human - turned - Pokemon has some special power or value.
If Kurama becomes Naruto's father in fanfiction, it could completely change Naruto's character development. He might inherit more of Kurama's powers directly. For example, he could have better control over the Nine - Tails' chakra from the start, without having to struggle as much as in the original story.
His Pikachu would probably be very supportive. It would stay by his side as he studies, maybe even help him in small ways like fetching medical tools. It trusts Ash completely and would be happy to see him pursue something new.
One idea could be that Naruto discovers a strange portal that transports him to the Pokemon world. Since he has his ninja skills, he quickly adapts. He might start by befriending Pikachu, as it's one of the most iconic Pokemon. His goal could be to become a Pokemon master, using his determination from being a ninja.