One example could be a story where the characters from Harry Potter find themselves in the world of Final Fantasy 8. Maybe Harry uses his magic in the same way Squall uses his gunblade, creating unique battle scenarios. Another could be a crossover where the spells in Harry Potter are combined with the junction system of Final Fantasy 8, leading to some really interesting power - ups for the characters.
There might be a fanfic where the Hogwarts houses are related to the SeeD classes in Final Fantasy 8. For instance, Gryffindors could be like the SeeD warriors, brave and always ready for a fight. The Slytherins could be more like the strategists in Final Fantasy 8, using cunning to achieve their goals. This kind of comparison and crossover can create a whole new world of stories.
A great fanfiction idea could be a story where the Dark Arts in Harry Potter are equated with the sorcery of Ultimecia in Final Fantasy 8. The characters from Harry Potter have to face a threat similar to Ultimecia, and they use their own magical knowledge and skills, along with some of the abilities they learn from the world of Final Fantasy 8, to combat this great evil.
One example could be a story where the magic system from Harry Potter is merged with the technological and crystal - based powers in Final Fantasy XIII. For instance, characters from the Harry Potter world might use wands to access the power of the crystals in Final Fantasy XIII. Another could be a crossover where the characters have to travel between the two universes, like Harry and his friends ending up in the world of Final Fantasy XIII and having to adapt to its rules and help the locals fight against a common enemy, perhaps an evil force that threatens both worlds.
One great fanfiction could be about a wizard from the Harry Potter world being transported to the world of Final Fantasy 13. Maybe they have to learn the new magic system there while also trying to find a way back home. It could be full of exciting battles and new friendships.
One interesting fanfiction could be a crossover where the magic from Harry Potter meets the high - tech world of Final Fantasy 7. For example, imagine Harry and his friends being transported to Midgar and having to deal with Shinra while also using their magic. There are likely some out there that explore how the different magic systems interact, like how materia could be related to wand magic. Another aspect could be the characters' reactions to the different cultures. Harry might be shocked by the slums in Midgar, while Cloud and his group could be intrigued by Hogwarts and its secrets.
One idea could be a crossover where Sephiroth somehow ends up in the wizarding world of Harry Potter. Maybe he's a dark force that Voldemort tries to use for his own gain, but Sephiroth has his own agenda. He could use his powerful magic, which is different from the magic in the Potterverse, to create chaos.
One example could be a story where the magic from Harry Potter is introduced into the Star Wars universe. Maybe the Jedi could learn spells like the wizards in Hogwarts. Another could be a crossover where Harry Potter characters find themselves in the Star Wars galaxy and have to adapt to the use of the Force instead of magic. For instance, Harry could be mistaken for a young Jedi in training.
There could be a crossover where some of the characters from Harry Potter end up in the Assassination Classroom. Harry, Hermione, and Ron might find themselves in the classroom, and they'd bring their own set of skills and knowledge. Hermione would probably be very interested in Koro - sensei's unique biology and try to figure out how to use magic to defeat him based on that knowledge.
One great example could be a story where a wizard from the Harry Potter world discovers ancient Valyrian magic spells. This could lead to all sorts of interesting plot twists, like using the powerful Valyrian magic to combat dark wizards in the Harry Potter universe. Another could be a crossover where a character from the Valyrian era is transported to Hogwarts and has to adapt to the different magical system there.
There could be fanfictions where characters from Harry Potter end up in the World of Warcraft universe and encounter Sylviana - like perhaps Hermione using her magic knowledge to solve some of the Warcraft's mysteries while teaming up with Sylviana. However, it's quite a niche combination, so finding existing examples might be a bit challenging. One could start by looking in specialized fanfiction archives and forums dedicated to crossover stories.
I'm sorry I can't directly give specific examples as there are so many out there and it's hard to pinpoint just a few. But generally, it could be a story where Hermione Granger and a Final Fantasy mage - like character go on an adventure together. Or Harry Potter might end up in a world similar to a Final Fantasy setting and befriend a character from there, and their relationship develops in a way that is the focus of the'slash' aspect.
One interesting crossover could be the use of magic systems. In Harry Potter, magic is more about spells and incantations, while in Final Fantasy 12 there are various magicks like black, white, and green magick. A fanfiction could explore a character from Harry Potter learning the magick system of Final Fantasy 12, perhaps Hermione trying to study the more scientific approach to magic in Final Fantasy 12.