Maybe Natsu founds Fairy Tail as a way to search for other dragon slayers. He believes that by creating a guild, he can attract more dragon - related magic users and together they can uncover the mysteries of their powers and their dragons' disappearances. So the story could revolve around this search within the framework of building and growing Fairy Tail.
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 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.
I'm not sure who 'natsu' specifically is as the founder of Fairy Tail fanfiction. There could be many people creating fanfiction and using the name Natsu in their works. It might be a self - given title by an individual within the fan community.
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.
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.
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.
In fanfiction where Natsu is the founder of Fairy Tail, the guild's culture would likely be heavily influenced by him. Natsu is known for his impulsiveness and his love for a good fight. So, the guild might have a more aggressive stance towards challenges compared to other interpretations. His relationships with the other main characters would also be re - imagined. For instance, his relationship with Lucy could be more of a mentor - mentee relationship at first, with Natsu guiding Lucy on how to be a true Fairy Tail mage. Also, the guild hall might have been built in a location that has a special significance to Natsu, perhaps a place where he had a memorable encounter with Igneel. And the guild's rules might be more lenient in some aspects, because Natsu is not one for strict regulations, but rather values loyalty and camaraderie above all else.
One popular storyline could be Natsu and Kinana going on an adventure together to find a rare magical item. This would test their skills and friendship as they face various obstacles along the way.
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.