naruto is trained more serious fanfic

One possible trainer could be Kakashi. He might take Naruto's training more seriously and push him to his limits. Kakashi has a lot of experience and knowledge, and he could use more extreme methods to train Naruto.

Well, he might start with more intense physical drills. Like running longer distances with heavier weights. This would build his stamina and strength much faster than before.

Kosuke might be a character created specifically for this fanfic. He could be someone with a unique background, like perhaps he was once a disciple of a great ninja but then went on his own path. And now he sees potential in Naruto and decides to train him. He could have abilities that are different from the main characters in the original Naruto series, which is why he has something new to offer to Naruto in terms of training.

In this fanfic, Lilith could be an original character created by the author. She might be a powerful and mysterious figure with special abilities that make her suitable to train Naruto.

She could be someone with a special bloodline or ability. Maybe she has a unique form of chakra that gives her certain powers. In the context of training Naruto, her skills and knowledge are what make her important. She could be a mysterious figure who has been observing Naruto for a while and decides to take him under her wing to help him reach his full potential. For instance, she might have the ability to see the latent potential in others and wants to shape Naruto into a great ninja not just for his own sake, but also for the greater good of the ninja world.

It could lead to Naruto becoming even stronger and more skilled than in the original story. Jiraiya's training methods might unlock new powers for him.

It could lead to Naruto developing much stronger abilities earlier and having a different path of growth.

One common theme is self - discovery. Just like in the original Naruto story, characters in fanfics often go through a journey of understanding themselves better. Another theme is redemption. For example, characters who made mistakes in the original story might seek to make up for it in the fanfic. And of course, the theme of friendship and loyalty still holds strong, as it was a big part of the Naruto series.

It could be really exciting. Guts' brutal and unyielding training methods might make Naruto even stronger. Naruto could learn to face his enemies with more tenacity from Guts. For example, Guts' way of fighting in close combat could be incorporated into Naruto's combat style, adding a new dimension to his abilities.

Well, Naruto might become extremely powerful in terms of his mental manipulation skills. Aizen is known for his cunning and ability to deceive. Naruto could learn new ways to outwit his opponents. He might also gain some unique combat techniques that are more psychological in nature, rather than just relying on his physical strength and ninjutsu.