Another idea is that there is a prophecy in the Fairy Tail world that a 'foreign hero' (Naruto) will come and help defeat the most powerful Dark Guild. So Naruto arrives, teams up with some Fairy Tail members, and they go on an adventure filled with battles, character development, and discovery of new abilities as they face the Dark Guild.
One possible fanfiction could be about a character from Naruto being transported to the Fairy Tail universe and getting involved with a Dark Guild. Maybe Naruto's skills in combat and his never - give - up attitude would help him either infiltrate the Dark Guild to gather information for Fairy Tail or try to reform some of the members.
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.
Jellal from the dark guild is quite memorable. His complex backstory and his struggle between good and evil make him stand out. He has great power and his actions often have a big impact on the story.
The internal structure and hierarchy of the dark guilds are also fascinating. There could be a complex system of loyalty, betrayal, and power acquisition within the dark guilds. Some members might be trying to climb the ranks by any means necessary, creating a lot of drama and intrigue.
The Fairy Tail guild would probably be very curious about Naruto at first. They might be amazed by his strange abilities like running up walls and creating clones. Some members, like Lucy, would likely be a bit cautious, but also intrigued. Natsu would probably be eager to test his strength against Naruto right away.
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.
It could lead to a change in the guild's dynamics. Naruto has his own unique combat style and abilities. His departure might make the guild realize the need to diversify their fighting strategies. For example, they might start to look for members with skills similar to Naruto's ninja techniques.
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 Goblin's Tail is a popular fantasy novel that many readers like. The Dark Guild refers to an organization whose purpose I'm not sure about because it may have different meanings in different storylines. However, people from the Dark Guild had appeared in many of the fairy's tail doujinshi novels, and these novels might have a protagonist.
She would fit in very well. The Fairy Tail guild is all about family and acceptance. Given her parents are Lucy and Natsu, she'd be welcomed with open arms. She could learn from the older members like Makarov and Mirajane, and bond with the younger ones like Romeo. Her magic skills would also contribute to the guild's strength during battles or when helping the town.
One possible interesting plot could be Naruto, as the guild master, having to deal with a powerful dark guild that is threatening the safety of Fairy Tail. He could use his ninja skills and leadership to gather the members and come up with a unique battle strategy.