If in the fanfiction Natsu reveals his dark past, it might change how readers/viewers see his relationships. For example, they may understand his protectiveness over certain characters better as it could be related to his past experiences. Also, it could make his character more relatable as many people have their own dark pasts to deal with.
It could make him seem more vulnerable. Usually, he might come across as strong and fearless, but revealing his dark past shows he has his own insecurities and traumas.
It could be about Natsu finally opening up about a tragic event from his childhood that shaped his personality. Maybe it involves the loss of a loved one, or an experience that made him distrust a certain group of people.
His friends could be involved. For example, Lucy might stumble upon some old records or meet someone who knew Natsu in the past. Gray could also be part of it, especially if it has something to do with the magic world's secrets that they both are a part of.
One of the senior and more experienced members of the guild. They have seen a lot and know how things should be done in the guild. If Natsu acts in a way that goes against their long - established ways, they would not hesitate to berate him.
His character could become more conflicted. He has to balance his old values from Fairy Tail with the new, darker ones of the guild he joined.
In the fanfiction, the release of Natsu's power might be detailed in terms of the emotions he's feeling at that moment. For example, if he's angry, his power might come out more violently and chaotically. It could also be described in relation to the magic he uses, like the way his fire magic swirls around him and grows in intensity before being unleashed.
The fanfiction can create new plotlines. If it reveals something unexpected about Natsu's past, like a connection to a dark magic or a hidden enemy, it could lead to new adventures and conflicts within the Fairy Tail universe. It might also change the way other characters view Natsu, leading to different interactions.
He might meet a powerful wizard who is the ruler of that dimension. This wizard could initially be hostile towards Natsu, seeing him as an intruder, but later they could become allies.
If Natsu is a girl in this fanfiction, her character might change in terms of her relationships. For instance, she may be more self - conscious about her appearance compared to when she was male. Also, her interactions with male characters like Gray could shift. Instead of their typical rival - like banter, there could be a more complex emotional undertone, like a friendly - rivalry with a hint of romantic tension perhaps.
Emotionally, Natsu could become more empathetic. If he meets characters in the dark guild who had a difficult past that led them to the dark side, he might start to see things from their perspective. This doesn't mean he would support their actions, but he would understand them better. For example, if there's a character in the dark guild who was orphaned and turned to dark magic for survival, Natsu might feel sympathy for them and try to offer an alternative path rather than just attacking them. This would show a more mature and compassionate side of his character that wasn't as prominent before.
Well, it could start with Natsu accidentally stumbling upon a time - related magic or a magical artifact that transports him to the time when his past self exists. Then they would meet and there would be a moment of shock and confusion.