It could be that Natsu creates a dark guild to protect something or someone. He realizes that the normal guilds' ways are too restrictive and might not be able to safeguard what he holds dear. His dark guild then becomes a sort of underground protectorate. They operate in the shadows, using their magic to fend off threats that the regular guilds are either unaware of or unable to handle.
Well, one possible plot could be that Natsu, after some sort of betrayal in Fairy Tail, decides to create his own dark guild. He might gather some disgruntled mages who also feel wronged by the mainstream guilds. Their goal could be to change the magic world's power structure in a more radical way, using darker forms of magic that are usually shunned. For example, they could explore ancient and forbidden magic spells to gain an edge over other guilds.
In this fanfiction, the characters would have to adapt to a more cutthroat environment. Natsu's friends from Fairy Tail who might join him in the dark guild would struggle with their new identities. They would have to learn to use magic in more aggressive and unorthodox ways. Their moral compasses would be tested as they engage in activities that are considered 'dark' in the magic world. Some might even have a complete character transformation, going from good - natured mages to feared members of the dark guild.
He might lose his friends at Fairy Tail. Since Fairy Tail is all about friendship and light, joining a dark guild would put him at odds with his former comrades.
The guild could be a place for ninjas from different villages to come together. Naruto, believing in unity among all ninjas, creates a guild that accepts members regardless of their village origin. This would cause some initial friction as old rivalries and suspicions surface. But Naruto, with his charisma and determination, would work towards building trust among the members. The guild's main goal could be to fight against a new, greater threat that endangers all the ninja villages, and they would need to put aside their differences to succeed.
Well, one possibility could be that Natsu leaves the guild because of a personal mission. Maybe he discovers a dark secret about his past that he believes can only be solved alone, so he leaves Fairy Tail to find out the truth without putting his friends in danger.
She might start by having Lucy grow disillusioned with the normal guilds. Maybe she's been mistreated or feels restricted. So, she decides to gather like - minded mages who also have issues with the existing guild system. They could start small, doing jobs that are a bit on the edge of legality. As they gain power and members, they face opposition from the regular guilds. This could lead to epic battles and a lot of character development for Lucy as she struggles between her old ideals and the new, darker path she's chosen.
The plot could involve Naruto being an outcast in the ninja world after some false accusations. The dark guild offers him a place where he feels accepted. However, the guild's activities are against the values he once held. So he has to decide whether to stay and try to change the guild from within or break away and face the consequences of having associated with them in the first place. It could also lead to some interesting battles where Naruto uses his unique skills against his former comrades who now see him as a threat.
The plot could revolve around a new Dark Guild that is formed specifically to take over both the Naruto and Fairy Tail universes. They start by stealing important artifacts from both worlds. Naruto and a team of Fairy Tail's strongest mages are brought together by a mysterious force to stop this new threat. As they investigate the Dark Guild, they discover that the guild's leader has a personal vendetta against both Naruto and Fairy Tail. This vendetta drives his actions and makes him a formidable foe. In the end, through teamwork, strategy, and the unique powers of both Naruto and Fairy Tail, they are able to defeat the Dark Guild and restore peace to both universes.
The 'natsu dark past secret fanfiction' might revolve around Natsu's family. There could be some dark secrets about his family that he has just discovered. Maybe his family was involved in some sort of dark magic or a feud with another powerful group, and Natsu is now starting to uncover the truth about 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.
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.