One great 'natsu uses fairy magic' fanfiction is 'Fairy Tail: Natsu's New Power'. In it, Natsu discovers a new way to use his fairy magic which leads to some amazing battles against powerful foes.
Well, in a 'natsu uses fairy law fanfiction', it often showcases Natsu's power in a more creative and unique way. Fairy Law is a very powerful spell in the Fairy Tail universe, and when Natsu uses it in fanfiction, it could lead to different plot developments. Maybe he uses it to defeat a much stronger enemy than in the original story, or perhaps he uses it in a way that reveals new aspects of his character, like his growth in controlling such a powerful magic.
One possible theme could be power and responsibility. Since Fairy Law is a powerful spell, Natsu using it might come with the need to be responsible for the consequences. Another theme could be friendship. His friends may be involved in the situation where he uses Fairy Law, and their support or lack of it could be explored.
One idea could be Natsu getting a new, powerful form during the Grand Magic Games. This form could be a result of some ancient magic he discovers. He then uses this form to defeat a really tough opponent and surprises everyone, including his guildmates.
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.
A great plot twist could be that Natsu loses his magic power right before a crucial match in the Grand Magic Games. But then he discovers a hidden reserve of power within himself, perhaps related to his past or his dragon heritage. This new power allows him to come back stronger and win the match in an unexpected way.
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.