Perhaps the Sage of Six Paths could be his mentor. Since the Sage has great knowledge and power, he could guide Naruto in understanding and using soul magic. Another option could be Jiraiya. Even in death, Jiraiya's spirit could communicate with Naruto and teach him about soul magic through visions or dreams.
Well, it could be Naruto himself, but with new abilities related to soul magic. He might be the one to discover this new form of magic and use it to protect his village in a different way.
One interesting concept could be the unique ways soul magic is integrated with the Naruto universe. For example, it might involve using soul magic to enhance jutsu or to communicate with spirits in a way that's different from traditional Naruto techniques.
In many of these fanfictions, Naruto uses magic to surprise his opponents. For example, he might use magic to teleport behind an enemy instead of using the normal ninja body - flicker technique. Magic gives him an unexpected advantage.
Well, in the fanfic, Naruto using crystal release could be part of a mission. Maybe he's in a land where crystal release is common among the enemies. He starts to study their techniques and somehow manages to adapt it to his own style. He could then use it to save his friends during a really tough fight. Like, he creates a huge crystal shield to protect everyone from a massive attack and then turns the shield into sharp projectiles to counter - attack.
In a fanfic where Naruto uses haki, it could change his relationships with other characters too. For example, if he shows this new power, some characters might be in awe of him, while others might be jealous. His training to master haki could also lead to new interactions with mentors or allies who are familiar with this power. Also, his use of haki could potentially attract the attention of new enemies who are interested in this unique ability.
Well, a plot could revolve around Naruto using soul magic to bring back the souls of those who were wrongly killed in the ninja wars. This would not only show his power but also his compassion. He might also use it to explore the afterlife and gain new jutsu or knowledge from there. And he could use soul magic to bind the souls of his friends together in a time of great crisis, creating a super - powerful united front.
If Naruto uses magic in fanfiction, it could completely change the power dynamics. For example, his normal jutsu might be replaced or enhanced by magic, making him even more powerful against his foes. It could also lead to new alliances as those who are interested in magic might seek him out.
One could be 'Naruto's Magical Ascent'. In this fanfiction, Naruto discovers his magic abilities when he's constantly neglected by the village. He uses his newfound magic to prove his worth in unique ways, like creating illusions that are far more powerful than normal ninja jutsus. Another is 'Magic - Naruto's Hidden Power'. Here, Naruto's magic is tied to an ancient and forgotten art that he stumbles upon during his lonely times. It gives him an edge in battles and helps him gain the respect he always deserved.
Well, there are some out there. The idea of Naruto using dragon slayer magic is really cool. In these fanfictions, Naruto could potentially gain new powers and face different kinds of challenges. For example, he might use the dragon slayer magic to fight stronger enemies that his normal ninja skills couldn't handle. It's a great concept that allows for a lot of creativity in the fanfiction world.