One possible plot could be that Natsu discovers his new power as a war god slayer magic user. He then has to face a series of powerful enemies who are threatening the world. Along the way, he might meet new allies who also have unique magic abilities. As he battles these foes, he gradually masters his war god slayer magic and becomes a more powerful wizard.
It could be another powerful mage who is jealous of Natsu's new war god slayer magic and wants to steal it for himself. This mage might have been researching ways to gain such powerful magic for a long time and sees Natsu as an obstacle to his own plans.
One idea could be that Naruto discovers a hidden power within himself that is related to God Slayer Magic. This new power could change the way he battles enemies in the Naruto universe. For example, he might be able to use it against powerful foes like Madara or Kaguya, giving him an edge he didn't have before.
Power and responsibility is a common theme. As Natsu becomes a dragon god slayer, he has more power, but also more duties. Another theme is friendship. His friends in Fairy Tail still support him even as he changes. And there's often the theme of self - improvement, as Natsu has to master his new abilities.
One idea could be Natsu discovering new and more powerful fire-based spells as a Fire God Slayer. Maybe he has to face a powerful ice - based enemy that forces him to tap into deeper levels of his god - slayer magic. This would make for an exciting action - filled fanfiction.
In a Naruto learns God Slayer magic fanfiction, it could be really exciting. Naruto's already powerful ninja skills combined with God Slayer magic would make him an even more formidable force. He could use the magic in battles against tough enemies like Akatsuki members. Maybe he'd learn it from a mysterious character who travels between different dimensions, and this new power would give him an edge in protecting the Hidden Leaf Village.
One great 'Fairy Tail Natsu Dragon God Slayer' fanfiction is 'The Dragon's Ascent'. It really delves into Natsu's growth as a Dragon God Slayer in a unique way. The author creates new challenges for Natsu that are both exciting and in - line with the Fairy Tail universe.
One way Naruto could learn God Slayer magic in fanfiction is through a magical artifact. He might stumble upon an ancient relic during one of his missions that imparts the knowledge of God Slayer magic. Another possibility is that he meets a powerful mage who decides to teach him the magic in exchange for a favor, like helping to protect the mage's homeland.
The God Slayer Magic might change Naruto's view of power. He has always been focused on his ninja way and his goal to become Hokage. But with this new magic, he would have to reevaluate what power means and how to use it responsibly. He might start to see that there are different forms of power beyond just ninjutsu and chakra. This could lead to a more complex and mature Naruto in the fanfiction.
Another aspect is the world - building. Since it's set in the Fairy Tail universe, the fanfiction should expand on the existing lore. Maybe introduce new dragons or aspects of the Dragon God Slayer magic that we haven't seen in the original series. This makes the fanfiction feel like a natural extension of the Fairy Tail world.