First, you need to understand the two universes well. Know the rules of magic in Fairy Tail and the nature of demigods in Percy Jackson. Then, create a unique plot. Maybe a crossover event that brings the two worlds together in an unexpected way, like a powerful dark force that threatens both.
A really interesting fanfic in this genre is 'Fairy Tail's Demigod Adventure'. It delves deep into how the powers from Percy Jackson's world would interact with the magic in Fairy Tail. For example, how a demigod's strength would fare against a Fairy Tail wizard's spell. It has a great plot that keeps you hooked from start to finish.
You can start by looking on popular fanfiction websites like FanFiction.net or Archive of Our Own (AO3). These platforms have a large collection of fan - created stories, and you can simply search for 'Percy Fairy Tail' in their search bars.
One great Percy Fairy Tail fanfiction could be one where Percy joins the Fairy Tail guild and goes on adventures with Natsu and the gang. He might use his water - based powers in combination with the magic of Fairy Tail, creating unique battle scenarios.
One interesting concept could be crossovers of the characters. For example, imagine Percy Jackson using his water powers in the world of Fairy Tail, perhaps teaming up with Natsu to fight a common enemy that is both a threat to the demigods and the wizards. It could lead to really cool battle scenes and unique character interactions.
Well, in some fanfictions, they might connect through the concept of magic. Since both Fairy Tail and Percy Jackson deal with magic in their own ways. The 'god soul' could be a concept borrowed from Percy Jackson's world of gods and demigods and be incorporated into the Fairy Tail universe in the fanfiction. Maybe a character in the fanfic has a god soul which gives them special powers similar to the magic in Fairy Tail.
It adds more content. The official Fairy Tail series has a limited number of episodes and chapters. Fanfiction fills in the gaps. For example, it can create stories about what the characters were doing during the time - jumps in the original story.
If Lucy never joined Fairy Tail, the friendships and relationships among the characters would form in a very different way. Also, many of the story arcs might not unfold as they do in the original plot.
Annabeth Chase is also a common crossover character. Her intelligence and strategic thinking can play well in the Fairy Tail world. She could potentially befriend characters like Lucy, who also rely on their wits at times. They might exchange knowledge about different mythologies and magic, creating an interesting dynamic between the two.
One popular theme is alternate universes (AUs). Writers like to explore what would happen if the Fairy Tail characters were in different settings, like a modern - day high school or a steampunk world. Another common theme is romance. Fans often pair up their favorite characters in different relationships, such as Natsu and Lucy or Gray and Juvia.