Natsu might start to question his abilities. Since he's so tired, he may think that he's losing his edge as a dragon slayer. This could lead to an internal struggle where he has to overcome self - doubt. He might train in a different way or seek advice from the older members of the guild to get his strength back.
He could be less active in battles. Usually, Natsu is full of energy and jumps right into fights, but if he's tired, he might hold back or even need to be rescued by his comrades. This would be a new and interesting dynamic for the story.
Perhaps Natsu's tiredness causes him to be more emotional. He could be more irritable with his friends or more vulnerable. This would allow for deeper character development as his friends would have to deal with this new side of him. They could also discover new things about Natsu that they didn't know before, like his fears or insecurities.
A fanfiction idea could be that in a crossover, Natsu is tired because he's been on a long - term mission in a different realm. He returns to Fairy Tail not quite himself. The guild members start to worry as he doesn't have his usual energy for pranks or challenges. As the story progresses, he slowly regains his strength through the support of his friends and the familiar environment of the guild, and in the end, he's back to his old self ready for new adventures.
Natsu could end up teaming up with some unexpected allies from Tartaros. Maybe there are some members who have a change of heart and decide to help Natsu fight against the more evil elements within their own organization.
She could be a key figure in an ancient prophecy. For example, the prophecy might state that only the son of a certain dragon - slayer mother (Natsu's mother) would be able to defeat a great evil that threatens the Fairy Tail world. This would set Natsu on a path to discover his mother's identity and fulfill the prophecy.
Natsu could also be deeply hurt. He values his friends highly in Fairy Tail. If betrayed, he might isolate himself, doubting his own judgment in trusting people. This could lead to a period of self - discovery where he tries to figure out how to trust again. For example, he might recall the times when his friends in Fairy Tail were truly there for him and use those memories to heal and grow stronger in the face of this betrayal.
In such a fanfiction, Natsu might have become much stronger. Maybe he has mastered new fire - based magic techniques. He could also have new relationships within the guild, like closer friendships or even a romantic interest.
Well, in fanfiction where Natsu leaves the guild, he could become a sort of lone wolf. He might travel to far - off lands to discover more about his dragon - slayer powers or his past. This could lead to him meeting new and powerful allies or enemies. Without the support of the guild, he would have to rely solely on his own strength and wits. It could also make him a more serious and hardened character, as he no longer has the safety net of his Fairy Tail family.
Natsu could bring a more fiery and passionate leadership style. He'd probably be more action - oriented than the previous masters. For example, if there's a conflict with another guild, he'd be the first one to charge into battle, leading by example.
If Natsu and Zeref join Fairy Tail in fanfiction, it would change the dynamic of the guild completely. The other members would have mixed reactions. Some might be distrustful of Zeref due to his past actions. However, as time passes, they could see the good in him. Natsu and Zeref together could attract a lot of attention from outside forces. Enemies might target Fairy Tail more because of their combined power. But also, they could inspire the guild to become even stronger, with everyone striving to keep up with their new powerful comrades.
In this kind of fanfiction, the kid might have some unique abilities. Since Natsu is a dragon slayer, the kid could have an enhanced form of dragon slayer magic or a combination of different magics. For example, the kid could have the ability to not only use fire like Natsu but also manipulate wind to make the fire more powerful.
Well, if Natsu asks Lucy out in fanfiction, it could change the whole dynamic of the Fairy Tail group. Their friends would probably be super supportive, especially Happy. They could start exploring new places not just for quests but also for romantic getaways. And Lucy might write a new story about their relationship in her diary.