The concept of destiny could also be a shared element. In Naruto, characters often have a pre - determined path related to their powers. In Fairy Tail, there are prophecies and destinies for some characters. In fanfiction, the EMS in the Fairy Tail setting could be part of a character's fated journey, like being the key to fulfilling a great prophecy in the Fairy Tail universe.
One way is through power - up scenarios. For example, a character in the Fairy Tail fanfiction could obtain EMS - like abilities which enhance their existing magic. This could be due to some magical experiment gone wrong or right that fuses Naruto - style power with Fairy Tail magic.
First, you need to have a good understanding of all three universes. Know the powers, the characters, and the storylines. For example, in Naruto, EMS gives unique abilities, and in Fairy Tail, magic is diverse. Combine these elements in an interesting way. Maybe have a character from Fairy Tail gain EMS - like powers.
One interesting fanfiction could be about a character from Naruto who somehow gets transported to the Fairy Tail universe and has to deal with the magic there while still having their EMS powers. For example, Sasuke could end up in Magnolia and form an unlikely alliance with Natsu to fight a common enemy.
In that fanfiction, it might be designed that way. Naruto has incredible powers in his own series, like his various jutsu. If translated into the Fairy Tail world in fanfiction, his skills could potentially make him very powerful. But it also depends on how the author of the fanfiction interprets and balances the power systems of both universes.
The Sharingan in such a fanfiction could be used as a tool for a Fairy Tail character to gain an edge in their battles. They might initially struggle to control it, but as they learn more about it, they become a formidable force. For instance, they could use the Sharingan's genjutsu abilities to deceive opponents in the Fairy Tail battles.
In the Fairy Tail world, Naruto would bring his unique ninja abilities. For example, his shadow clone jutsu could be used in creative ways during battles or to perform tasks. He would likely befriend Natsu because they both have a passion for fighting and protecting their friends. Naruto could also introduce new combat styles to the Fairy Tail guild, which might change the way they approach battles.
Well, Naruto would probably gain some really unique magical abilities. Fairy Tail mages are known for their diverse magic, and Naruto could combine his chakra skills with something like Fire Magic or Celestial Magic. He might become even more powerful in combat, with new ways to attack and defend.
Well, Naruto's ninjutsu skills would be quite a novelty in the Fairy Tail world. His shadow clone jutsu could be used in some really creative ways during battles, like overwhelming opponents with a large number of clones. Team 7 as a whole would bring a different dynamic. Sasuke's sharingan could give them an edge in detecting magic and illusions. Sakura, with her medical skills, could be a great asset in treating wounded mages. And Kakashi, with his experience and wide range of jutsu, would be like a mentor figure to the Fairy Tail members, teaching them new strategies.
Well, if Naruto was in the S - Class of Fairy Tail, his combat skills would be a great addition. Naruto's ability to use shadow clones could be used for various strategic purposes during Fairy Tail's missions. He could send clones to scout ahead or create distractions in battles against dark guilds.