If Naruto is trained by Obito in fanfiction, his character would experience a significant shift. Obito has seen a lot of pain and loss, and his training might expose Naruto to a darker side of the ninja world. Naruto could become more calculating in his battles, rather than relying solely on his brute strength and determination. His relationships would also be affected. He might distance himself from some of his friends who don't understand his new path. However, he would also gain a deeper understanding of the Uchiha's plight, which could make him more empathetic towards enemies in the future.
Naruto might become more reserved. Since Obito has a more brooding personality, Naruto could pick up on some of that. His once - bright and exuberant nature might be tempered.
When trained by Ibiki in fanfiction, Naruto's character would experience a significant transformation. He'd lose some of his naivete. Ibiki's world is full of deception and danger, and Naruto would have to adapt. He'd become more calculating, weighing the pros and cons of his actions more carefully. His sense of humor might also change, becoming more dry and sarcastic as he gets used to Ibiki's gruff personality. His relationships with his friends could be affected too, as he might seem more distant at first while he adjusts to his new mindset.
When trained by Deidara in fanfiction, Naruto's view of art could change. Deidara has a very distinct view of art as something that is transient and explosive. Naruto might start to see the beauty in destruction in a way, which could make his character a bit darker. His attitude towards his enemies might also change. Instead of always trying to redeem them, he might be more willing to use forceful and destructive means to defeat them, as he has learned from Deidara's combat approach.
Naruto's confidence might increase. With Cus's training, he could master new skills more quickly, which would boost his self - assurance in battles.
He might become more disciplined. Gai's training is very structured, so Naruto would have to follow a strict routine, which could make him more organized in his approach to things.
The story would change a great deal. Naruto's power - up would be significant. He could face tougher enemies more easily. His friends might be both amazed and a bit worried about his new, more aggressive style. The overall tone of the story could shift towards a more action - packed and intense direction.
Naruto's fighting style would likely become more stealth - oriented. Since Obito is known for his ability to move undetected, he might teach Naruto some techniques to blend into the shadows and surprise his opponents. For example, Naruto could learn to use the environment to his advantage in a more subtle way, rather than his usual straightforward attacks.
The training by death would likely toughen Naruto up both physically and mentally. He'd probably have a darker, more determined edge to his character. He might be more solitary in his training, spending more time alone to master the skills death has taught him. This could make him seem a bit more distant to his friends initially, but in the long run, it would make him a stronger and more reliable ally.
Naruto becomes more confident. After the time - skip and toad training, he knows he has the skills to face tough opponents. He's no longer the underdog who doubts himself all the time. His appearance might also change slightly to reflect his growth. Maybe he has a more serious look in his eyes. His sense of humor could still be there, but it's more refined, not as brash as before.
When trained by Nagato in fanfiction, Naruto's character development would likely involve a growth in his understanding of power. Nagato has a different approach to power compared to Naruto. Through Nagato's training, Naruto may learn that power isn't just about physical strength but also about knowledge and the ability to make tough decisions. This could add a new layer of maturity to Naruto's character.
His character might become more cautious. Kakuzu is a cautious fighter, and Naruto could pick up this trait. He would be less likely to rush into battles without a proper plan.