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.
There are some great ones. Some focus on Natsu's growth and how he overcomes final challenges at the end of the Fairy Tail story. Others might explore his relationships in a more in - depth way as the story comes to a close. It really depends on what kind of story you're interested in. If you like action - packed endings, look for ones where Natsu is using his full power to save the day. If you prefer more character - driven stories, there are those that deal with his emotions and bonds with other characters at the end.
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.
Yes, in a lot of Fairy Tail fanfiction, Natsu can be overpowered. Writers often like to amp up his powers for more exciting storylines. For example, they might give him new fire - based abilities or make his existing ones even stronger to defeat more powerful foes.
In fanfiction, Natsu's age can vary greatly. Some authors might keep him at his canonical age from the original Fairy Tail series, which is around 17 - 18 years old at the start. However, in alternate universe fanfictions, he could be older or younger depending on the plot. For example, in a time - travel based fanfic, he could be much older if the story takes place far into the future or much younger if it goes back to his childhood days.
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 possible plot development is that Natsu, as END, could be hunted by various magical organizations who see him as a threat. This would put him on the run and force his Fairy Tail friends to either protect him or try to stop him if they believe he's too dangerous. Another development could be that Natsu discovers new abilities related to END that give him an edge in battles but also come with a cost, like draining his life force or affecting his mental state.
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.
One possible aspect of a Fairy Tail Natsu and Tartaros fanfiction could be Natsu's battle against the powerful foes in Tartaros. He might face new and terrifying enemies that test his limits. His dragon slayer magic would be put to the extreme, and perhaps he discovers new powers along the way.
In fanfictions like this, the character development of Natsu within the context of Sabertooth is interesting. He could learn new magic techniques from them or teach them his own unique brand of Fairy Tail spirit. It might also explore how the different cultures of the two guilds clash or blend.