Gray might show up too. He could start as a bit of a rival, not believing that Natsu can really achieve great things with this Dragon God training. But as the story progresses, he could become more of a supporter. And then there's Lucy. She might be worried about Natsu during the training, and also use her celestial spirit magic to help Natsu in some unexpected ways during his training, like summoning spirits that can provide unique challenges for Natsu to overcome.
Happy, Natsu's flying cat companion, would definitely be a main character. He would be there to provide comic relief as always, but also be a source of emotional support for Natsu during his transformation into a dragon god. Erza might also be a prominent character. With her strong leadership skills and powerful magic, she could be guiding the guild during the times when Natsu is still coming to terms with his powers and the changes it brings to the guild.
He might be more in tune with nature. Since dragons are often associated with nature, Natsu could have a deeper respect and understanding of the natural world around him, showing more kindness to animals and plants.
In addition to Lucy and Erza, there could be other female characters from the series. Maybe some minor characters who have always admired Natsu from afar. For example, that one girl from the guild who always blushes when Natsu is around. Another possibility is a powerful female dragon who sees Natsu's transformation into a Dragon God as a sign of his worthiness. She might join his harem, bringing a different kind of relationship dynamic as she has her own dragon - like qualities and power. And there could be a female mage from a different guild who hears about Natsu's new status and is intrigued, eventually becoming part of his harem.
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.
In this fanfiction, it might be that the Dragon God has a special purpose for training Natsu. It could be related to an upcoming threat to the magical world. So, the training is not just about making Natsu stronger, but also about preparing him to be a key figure in saving the world. The training might involve facing various challenges that are designed to test not only his physical strength but also his loyalty, courage and ability to make the right decisions.
In this fanfiction, a possible plot is that Natsu has to protect his friends from those who fear his new power as a dragon god. His friends initially might be a bit wary of him too. But as the story progresses, he shows them that he's still the same Natsu at heart. He uses his powers to save the guild from a great danger, like an invasion from a powerful dark force that only his dragon god powers can defeat.
In addition to Natsu, Wendy could be a main character in the 'natsu is a dragon god fanfic'. Since she also has dragon - related powers, she could have a special connection with Natsu in this new situation. Maybe she helps him understand more about his dragon god powers. And Makarov, as the guild master of Fairy Tail, would also be a significant character. He would be concerned about how Natsu's new status affects the guild and the magical world as a whole.
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.
Well, it could be about Natsu's journey to becoming a Dragon God and how he attracts a harem along the way. Maybe he gains new powers that make him irresistible to certain characters.