There could be a fanfiction where the Chakra system in Naruto is related to the Materia system in Final Fantasy. Characters would have to collect and use different types of Materia - like Chakra to gain new abilities. For instance, Sasuke could find a Materia that enhances his Sharingan. Another idea is a story set in a post - apocalyptic world that combines elements of both Naruto and Final Fantasy. The survivors, including Naruto characters, have to use both ninja skills and Final Fantasy powers to rebuild and defend their world.
A great Naruto Final Fantasy fanfiction idea is to combine the magic systems. In this story, shinobi could learn to use Final Fantasy - style magic, like black magic for offensive spells and white magic for healing. Or perhaps a plot where the Akatsuki is after a powerful crystal from the Final Fantasy world that could grant them ultimate power. Also, a fanfic about a character from Naruto traveling through different worlds of Final Fantasy, facing the challenges and enemies in each world.
One plot idea could be that Naruto is somehow transported to the world of Final Fantasy 13. There, he meets the characters and due to his unique abilities and charm, a harem starts to form around him. He could use his ninja skills to help the characters in their battles against the fal'Cie. Another idea is that the characters from Final Fantasy 13 are brought to the Naruto world. The different cultures and powers collide, and as the FF13 characters adjust, they are drawn to Naruto, creating a harem situation. The harem members could then team up with Naruto to protect both worlds from common threats.
One idea could be exploring the backstories of the minor characters. For example, the SeeD trainees who don't get much spotlight in the game. Another could be a 'what if' scenario, like what if Squall and Rinoa didn't end up together? It could also be interesting to write about the world of Final Fantasy 8 from the perspective of an ordinary citizen living in one of the cities, dealing with the sorceress wars and the chaos that ensues.
One idea could be to create an OC who is a mage from a long - lost tribe in Ivalice. They could have unique spells that are based on ancient tribal magic. Another idea is an OC that is a sky pirate with a mysterious past, perhaps related to the great airships of the game. Or an OC that is a knight trying to restore an old code of honor in a time of political unrest in the game's world.
One idea could be a crossover with the 'Harry Potter' universe. Squall could be a wizard, and his gunblade could be enchanted. Another could be a crossover with 'Star Wars', where the characters from Final Fantasy 8 are in the middle of the galactic conflict. Maybe Laguna could be a Jedi - like figure.
One idea could be exploring the backstories of the minor characters in more depth. For example, the story of the civilians in Cocoon who were affected by the events. Another could be a what - if scenario, like what if Lightning had made different choices at certain key moments. And a third could be focusing on the relationship between Fang and Vanille before they became l'Cie.
One idea could be exploring the backstories of the main characters in more depth. For example, Noctis' training as a prince and his relationship with his father before the events of the game. Another could be a fanfiction set in an alternate universe where the Astrals have different roles or relationships with the humans. Maybe a story where Noctis and his friends have to face a new, unexpected threat that wasn't in the original game.
One idea could be a crossover between Final Fantasy VII and Final Fantasy X. Imagine Cloud and Tidus teaming up to fight a new powerful enemy. Another could be a crossover with a non - Final Fantasy franchise like Pokemon. Picture Squall trying to catch Pokemon in the world of Final Fantasy VIII.
A possible fanfiction could involve a fusion of the two worlds' power systems. The characters from both Naruto and Final Fantasy 13 could exchange knowledge about their abilities. For instance, the summonings in Naruto could be related to the Eidolons in Final Fantasy 13, and they could find ways to combine their powers for a greater good.
One idea could be to have Naruto characters in the world of Final Fantasy 10. For example, Naruto could be a Blitzball player, using his speed and agility. Sakura could be a healer, like a White Mage in Final Fantasy 10. They could be on a quest to stop Seymour from achieving his evil plans, with Naruto's Rasengan being a powerful attack against the fiends in Spira.
One idea could be to have Naruto characters in the world of Final Fantasy 15. For example, Naruto could be a guest in Noctis' group. He could use his ninja skills like shadow clones to help in battles against the daemons in Final Fantasy 15. His chakra could be seen as a new form of magic in that world.