In this fanfiction, perhaps Natsu's return as a 'king' means he has a new level of leadership. He might bring back some lost magic or knowledge that helps Fairy Tail regain its former glory. For example, he could have found a way to defeat an old enemy that was once too powerful for the guild. His return could also stir up emotions among the guild members, like excitement, relief, or even some jealousy from those who might have risen in his absence.
Natsu is the central figure in this fanfiction. But other characters like Happy, his loyal flying cat companion, will surely play an important role. Makarov, the guild master, would also be a main character as he has to deal with Natsu's return, whether it's a welcome or a bit of a shock to the guild's current state. And don't forget about the villains or antagonists that Natsu and Fairy Tail might face upon his return, they could also be considered main characters in the sense that they drive the plot forward.
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.
Often, it could be because of a false accusation. Maybe someone framed Natsu for a crime he didn't commit, like stealing a powerful magical artifact from the guild. So, to maintain peace and order, the guild leaders had no choice but to banish him.
Lucy could be a main character. She was always close to Natsu in the original Fairy Tail. So when Natsu returns as an 'ex' and meets the guild again, she would likely play a big role in how he is received and in the development of the story.
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.
One great fanfiction that delves into Natsu's memories might be titled 'Natsu's Hidden Past'. In it, the author could explore his early days in Fairy Tail, his relationship with Igneel, and how those experiences shaped the person he is today. It might show how he learned to control his dragon slayer magic and the friendships he formed along the way.
There might be. 'Fairy Tail' has a large fan base, and many fans enjoy creating fanfiction. Natsu, with his fiery personality and combat skills, could be an interesting Mandalorian in a fan - made story. It would be cool to see how his magic would interact with the Mandalorian technology and culture. However, I'm not sure exactly how many of such fanfictions exist, but it's definitely a concept that could work well.