One way it could be possible is if Naruto somehow gains access to the knowledge of the Hiten Mitsurugi - Ryu through some sort of cross - dimensional encounter. Maybe a rift in space - time brings a master of the style to the Naruto universe, and Naruto, being the curious and quick - learning ninja he is, starts to study and adapt it to his own combat style.
In a more creative fanfiction scenario, Naruto could be put under a genjutsu that makes him experience the life of a swordsman who practices the Hiten Mitsurugi - Ryu. As he goes through this 'virtual' training, he unconsciously starts to develop the skills of the style. When he breaks free from the genjutsu, he still retains some of that knowledge and begins to experiment with creating his own version of the Hiten Mitsurugi - Ryu.
Well, in a fanfiction world, it could happen if there was some sort of cross - dimensional or time - traveling event. Maybe Naruto stumbles upon a portal that leads him to the world where the Hiten Mitsurugi - Ryu exists. There, he meets a master of the style who sees potential in Naruto and decides to teach him.
It can change the power dynamics. For instance, if a minor character masters the Hiten Mitsurugi - Ryu, they might suddenly become a more formidable opponent, changing the course of battles.
One popular Hiten Mitsurugi - Ryu Naruto fanfic could be one where a character uses the techniques from Hiten Mitsurugi - Ryu in the Naruto universe in unique ways. For example, they might combine it with ninjutsu to create new combat styles.
Naruto's version of the Hiten Mitsurugi - Ryu could be more chakra - based. He might use his chakra to enhance the speed and power of his sword strikes, similar to how he uses chakra to power up his shadow clones. His sword could also be a unique creation, perhaps made from a special chakra - infused metal that can withstand his powerful attacks and also channel his chakra more effectively.
He could learn it from a crossover character. If there's a character from Rurouni Kenshin in the fanfic, that character might teach Naruto the Hiten Mitsurugi. For instance, if Kenshin himself is in the story, he could see potential in Naruto and decide to pass on his knowledge of this sword technique.
His speed would likely increase significantly. The Hiten Mitsurugi - Ryu is known for its fast and fluid sword movements, so Naruto would need to adapt to this new speed. He might start using more acrobatic maneuvers during combat, like leaping and spinning in ways he didn't before.
Yes, in some fanfics Naruto might know the Hiten Mitsurugi. Fanfic writers often like to cross different elements from various anime or manga. They could create a scenario where Naruto, being a curious and adaptable character, somehow comes across the Hiten Mitsurugi technique and learns about it. This could be part of a story where Naruto travels to different worlds or meets characters from other series.
Perhaps the fanfiction could revolve around Naruto time - traveling to the world where Ryu Hayabusa exists. There, he witnesses Ryu's battles and is in awe of his strength and honor. Naruto then decides to train under Ryu to become stronger. During this training, Naruto has to adapt to a different style of combat without his usual ninja tools. He learns to rely more on his body and speed, like Ryu. This experience changes Naruto's perspective on fighting and when he returns to his own world, he brings back a new sense of confidence and fighting ability.
One reason could be to explore a darker side of the Naruto world. Writers might want to see how Naruto's character would develop under extreme circumstances. Another reason could be to create a contrast. By showing Naruto being abused by everyone, it makes the positive aspects of his relationships in the original series seem even more significant.
Some creators might want to explore a darker side of Naruto's character. Maybe they're tired of the always - positive and heroic Naruto and want to see what he'd be like if pushed to the extreme.