Another interesting concept is to have the chakra system from Naruto integrated into the FF7 universe. Maybe the materia could be enhanced by chakra, or characters could learn to use jutsu instead of magic. For instance, Aerith could learn some healing jutsu to add to her abilities.
A FF14 crossover fanfiction could involve crossing over with the 'Harry Potter' universe. The mages in FF14 could attend Hogwarts and learn different forms of magic. Or, a crossover with the 'Star Wars' universe. The Jedi and Sith powers could be compared and contrasted with FF14's dark and light magic. Also, a crossover with the 'Pokémon' world. The players in FF14 could capture and train Pokémon alongside their normal adventures.
A cool 'ff7 crossover fanfiction' idea could be to cross it with the 'Star Wars' universe. Picture Sephiroth as a Sith Lord, with his powerful abilities and dark charisma. He could face off against Jedi Knights. Or perhaps Aerith could befriend some of the more force - sensitive characters in the Star Wars universe. Another option is to crossover with the 'Mass Effect' series. The technology in Mass Effect could be an interesting contrast to the more magic - based elements in FF7. Characters like Tifa could interact with the alien species in Mass Effect.
One idea could be a crossover with another popular RPG like 'Dragon Age'. Imagine the characters from FF13 in the world of Thedas, dealing with the different races and magic systems there. Another idea is a crossover with a sci - fi universe like 'Mass Effect'. The technology and alien species in that universe would create a really unique setting for the FF13 characters. Or perhaps a crossover with a classic fantasy like 'The Lord of the Rings'. The FF13 characters could interact with hobbits, elves, and dwarves, which would be quite a sight.
One idea could be Naruto being summoned into the world of FF14. He might initially be confused but quickly adapt his ninja skills to the new environment. For example, his ability to use chakra could be translated into a unique form of magic in FF14.
One idea could be a Naruto and One Piece crossover. Naruto and Luffy could meet and have to team up to defeat a common enemy that threatens both their worlds. Maybe a powerful dark force that can manipulate the sea and the land.
One idea could be exploring the backstory of an original character (OC) within the world of FF7. For example, an OC who is a SOLDIER trainee but has a secret connection to the Ancients. Another could be an OC who is a merchant in Midgar, dealing with the various gangs and Shinra's influence. And also, an OC who is a researcher studying the effects of Mako on the planet.
One idea could be creating an OC who is a powerful mage from a hidden village. They could join the main characters on their journey and use their unique magic to help in battles. For example, magic that can manipulate time briefly to give an advantage in combat.
Well, one interesting idea could be the combination of Naruto's ninja skills with the powers from another fictional universe. For example, if Naruto were to cross over with the Harry Potter universe, his chakra-based jutsu could interact in unique ways with magic. Maybe he could use his Shadow Clone Jutsu to confuse Death Eaters while wizards try to figure out how to counter it with spells.
One idea could be that Naruto characters are transported to the AOT world. Naruto's ninjutsu skills would be a huge advantage against the Titans. For example, his Shadow Clone Jutsu could be used to distract the Titans while the Survey Corps make their moves. Another idea is that the Ackermans have some sort of connection to the chakra system in Naruto. Maybe they can unlock chakra and use ninjutsu, which would completely change the dynamic in the AOT world.
One idea could be that the characters from Naruto end up in the world of Blade. For example, Naruto himself might be mistaken for a powerful being in the Blade world. He could use his chakra powers in new and unexpected ways against the vampires in that world.