In some fanfictions, Natsu could be framed by a dark guild as a traitor to Fairy Tail. The dark guild spreads false rumors and evidence, causing Fairy Tail to turn against him. Natsu then has to prove his innocence while also taking on the dark guild that started it all. This would lead to a lot of internal conflict within Fairy Tail and also intense battles between Natsu and the dark guild members.
One possible storyline could be that Natsu is wrongly accused of a crime within the Fairy Tail guild. Maybe some false evidence is planted against him, leading the guild members to turn their backs on him. Another could be that a powerful enemy manipulates the guild into believing Natsu is a threat, so they betray him. It might also be that there's a misunderstanding about Natsu's powers or intentions, causing the betrayal.
One possible storyline could be Natsu founding Fairy Tail after a great battle where he realizes the need for a guild that stands for true friendship and strength. He then gathers like - minded mages and builds the guild from the ground up.
One possible storyline could be that the OC tries to find Natsu after he leaves Fairy Tail. The OC might have a special bond with Natsu and be determined to bring him back. They could go on a journey where they face various challenges and meet new characters along the way. Another idea is that the OC is actually the reason Natsu leaves Fairy Tail in the first place. Maybe there was a misunderstanding or a conflict between them that led to his departure, and the story could be about how they resolve it.
Well, there would probably be shock. Gray might make some sarcastic remarks at first. Happy would be very confused, not sure how to handle the situation. And Master Makarov would likely be concerned about how this would affect the guild dynamics and the two mages' future in the guild.
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.
He could leave because of a misunderstanding. Maybe he overhears something wrong and thinks the guild doesn't trust him or value him anymore. So in a fit of anger and pride, he decides to leave.
The story could also revolve around how the guild members' relationships change. For instance, Happy might not be as cheerful without Natsu around. And the guild as a whole might become more united in trying to find a replacement for Natsu or trying to figure out how to move forward without him. They could start to explore different parts of the magical world to find new allies or magic that can help them in their battles.
A common type of fanfiction might be a love story between them. Despite their different personalities, they could gradually fall in love. For example, during a long and dangerous quest, they start to see each other in a new light. Or perhaps a story where Mirajane's past traumas are revealed to Natsu, and he helps her overcome them, strengthening their bond in the process.
One popular storyline is about Natsu's journey to become stronger in the memory of Igneel. He often faces tough battles and overcomes them with the power Igneel instilled in him. Another is where Natsu discovers hidden secrets about Igneel's past that change his perspective on his own life and powers. And sometimes, there are fanfictions that feature Igneel coming back in some form to guide Natsu further in his adventures.
One popular storyline could be Natsu and Laxus teaming up against a powerful dark guild. They have different fighting styles but learn to combine their strengths. Natsu's brute force and Laxus' lightning - based attacks could make for some epic battle scenes.