Natsu's character development in this fanfiction might involve him becoming more responsible. With his end form, he has greater power and with that comes the need to use it wisely. He could start to think more about the consequences of his actions. For example, he might not rush into battles as blindly as he used to. Also, his emotional growth could be a part of it. He could become more in tune with his feelings towards his friends, especially Lucy. His loyalty to the guild could also deepen as he realizes his new form can be a great asset to protect Fairy Tail.
One interesting concept could be Natsu's enhanced power levels. In end form, he might have new and more powerful fire-based attacks. For example, he could create a massive inferno that not only burns but also has some kind of special effect like nullifying dark magic in the fanfiction world. Another concept could be his appearance. Maybe he has a more mature and fierce look, with his hair changing color slightly or his eyes glowing more intensely. Also, his relationships with other characters might be developed further. His bond with Lucy could become even stronger, and they could have new adventures together where his end form is crucial for their success.
Friendship and loyalty also play a big role. His friends in Fairy Tail have to accept and support him in his dragon form. In stories such as 'Bonds in Dragon Form', it shows how their relationships are tested and strengthened when Natsu reveals his dragon side.
Another aspect in fanfiction could be the relationship between Natsu's dragon form and the other characters. His friends might be in awe or even a bit scared at first when they see his new, more powerful form. For instance, Lucy could struggle to understand how much of Natsu is still himself when he transforms, and this could create some tension and interesting character development between them.
Sure, in the 'Fairy Tail' universe, the concept of Natsu being END is quite fascinating. Fanfiction writers often take this idea and run with it. They might create stories where Natsu discovers his true nature as END more gradually, or they could write about how the other guild members react when they find out. It can also lead to stories that explore the origin of Natsu as END and how it ties into the overall lore of the 'Fairy Tail' world.
Some fanfictions focus on Natsu's dragon form and its effect on his love life. For example, how his new form affects his relationship with Lisanna or Lucy. Does his more dragon - like nature attract them in a new way? Or does it create barriers that they need to overcome?
Another good one is 'The Dragon Within Natsu'. This fanfiction takes Natsu on a journey where his dragon form is not just a power, but a part of his identity that he has to embrace to save his guild and the world from a looming threat.
In some fanfictions where Natsu becomes END, it often leads to a power - up that is both amazing and terrifying. His physical appearance might change, with more demonic features. His power level could skyrocket, making him one of the most powerful beings in the Fairy Tail universe. He might struggle with the newfound darkness within him, as END represents a very powerful and potentially evil force. This could lead to interesting storylines where his friends in Fairy Tail have to find a way to bring back the Natsu they know while still dealing with the power of END that he now wields.