Perhaps in the fanfiction, Naruto's world is somehow merged with the Kingdom Hearts world. Xigbar could be a key figure in a conflict that Naruto gets involved in. Naruto, being the curious and adventurous type, could become a fan of Xigbar because of his unique fighting style and his knowledge of the strange new world they are in. It could also involve Naruto trying to adapt to the different rules and magic in the Kingdom Hearts universe with Xigbar as his guide or inspiration.
One idea could be that Xigbar has some knowledge or power that Naruto desires for his own village or for his own growth as a ninja. So Naruto becomes a fan in the sense that he admires Xigbar's abilities and wants to be associated with him. Maybe Xigbar has a way to enhance Naruto's chakra or teach him new combat techniques. And as Naruto gets to know Xigbar more, he becomes more and more of a 'fan', following his lead and getting involved in the events and battles of the Kingdom Hearts world.
I'm not sure if there is a specific fanfiction exactly like that. There are countless fanfictions out there, and while the Naruto and Kingdom Hearts (where Xigbar is from) universes are quite different, it's possible some creative writer has combined them in that way. But it's not a common or well - known concept that I'm aware of.
It could be about Naruto getting Cell's powers. Maybe through some strange ninja jutsu gone wrong or a magical encounter. He could then use these new powers in his ninja battles.
It could be about Naruto using his telekinetic powers to fight new and stronger enemies. Maybe he discovers this power during a difficult battle and has to quickly learn to control it to save his friends.
It could be about Naruto somehow ending up in Castiel's universe in Supernatural. Maybe he teams up with Castiel to fight demons or other supernatural threats.
Well, it might explore how Naruto's personality and actions change when he is in a state similar to being stoned. Maybe his usual energetic self becomes more laid - back and he approaches problems in a different way in the fanfiction. It could also show how his friends react to this new, altered Naruto.
I'm not sure if there is a specific 'naruto is trigon fanfiction'. But if it exists, it might be a very strange and creative crossover. Maybe in this fanfiction, the world of Naruto somehow intersects with the concept of trigon, perhaps Trigon's powers are introduced into the Naruto universe and change the way ninjas fight or interact.
A 'Naruto is a wizard' fanfiction could involve Naruto being transported to a wizarding world. There, he would have to adapt to the new rules and magic system. He could bring some of his ninja traits, like his determination and loyalty, and use them to overcome challenges in this new magical environment. For example, he might use his shadow clone jutsu in a creative way within the wizarding world to solve problems or fight enemies.
One idea for a Naruto and Suzume fanfiction is that Suzume has a special object that the bad guys in the Naruto world want. Naruto has to protect her and the object. Along the way, they discover that the object has a connection to both their worlds and they have to figure out how to keep it safe together.
In a 'Naruto is Zoom' fanfiction, it might start with Naruto waking up one day and realizing he has Zoom - like powers. He then has to deal with the consequences of having such extreme speed in a world that is not used to it. He might accidentally destroy things or scare his friends at first. As the story progresses, he could learn to control these powers and use them for good, like rescuing people faster or catching criminals in the ninja villages more efficiently. He could also face new enemies who are attracted to his new - found powers and want to steal them for themselves.
It could be about Naruto using his scientific knowledge to enhance his ninja abilities. For example, he might develop new types of jutsu based on scientific principles.