I recommend the two novels, One Piece: I'm a Big Boss and Naruto: The Demon's Law, to you. The main character of One Piece I Am a Big Boss became the West Ocean mafia in the world of One Piece. He ate the fruit of the Demon's Eye and became the world's big boss. Meanwhile, the main character of Naruto Demon Law, Medicine Master Yu, awakened the Demon Fruit in Naruto World, and the human puppets he created also had the ability of the Demon Fruit. I hope you like my recommendation.
The Fire Devil Fruit could make Naruto more confident. Having such a powerful ability would give him an edge in battles and make him feel more capable. This newfound confidence could also change how he interacts with his friends and allies. He might be more assertive in leading them.
The novel " Demon's Law " was a fantasy novel written by the author, Er Gen, about a world where laws were used as weapons and wars were fought between demons and humans. In this world, humans and demons coexisted, but humans had always tried to destroy the demons, while the demons were looking for opportunities to take revenge. In the war between humans and demons, a batch of excellent warriors and mages emerged. They used their wisdom and strength to play an important role in the war. At the same time, there were also some mysterious existences in this world. Their strength was so powerful that it was unimaginable. They were regarded as the ultimate power of the world.
If Naruto had the Fire Devil Fruit, his combat style would change drastically. He could combine his existing ninja skills with the power of the fruit. For example, he might be able to infuse his Rasengan with fire, making it even more powerful. Also, his mobility could be enhanced as he could use fire to propel himself in new ways. This would make him a more formidable opponent in battles against strong foes like Sasuke or Pain.