A cool 'Final Fantasy 8 Crossover Fanfiction' idea is to cross it with the 'Lord of the Rings' world. The GF system could be related to the magic in Middle - earth. For example, Ifrit could be a powerful being like a Balrog. Characters like Zell could be like hobbits in terms of their spunk and courage.
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.
You could do a crossover with the 'Matrix' series. The digital world in 'Matrix' could be linked to the world of Final Fantasy 8 in some way. The characters might discover that their world is also a form of matrix and have to fight against it while using their unique Final Fantasy 8 abilities.
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 'Final Fantasy VIII Crossover Fanfiction' could involve crossing it with the world of 'Alice in Wonderland'. Rinoa could be like Alice, falling into a strange world where everything is topsy - turvy. The Heartless from Kingdom Hearts could also be added to the mix in a crossover. The characters of Final Fantasy VIII would have to fight these new enemies, with Squall taking on the role of a keyblade wielder in this strange new world.
A crossover with the Star Wars universe could also be exciting. Imagine the characters of Final Fantasy 13 in a galaxy far, far away. Snow could be like a Jedi, using his strong will and combat skills, while Fang might be more of a bounty hunter type, roaming the galaxy in search of valuable prey.
One idea could be a crossover with another popular RPG like Dragon Quest. The characters from World of Final Fantasy could end up in the world of Dragon Quest, facing new enemies and having to adapt to different magic systems. For example, the mirages in World of Final Fantasy might interact in strange ways with the slimes in Dragon Quest.
Maybe the Philosopher's Stone in Harry Potter has some connection to a powerful crystal in Final Fantasy. Voldemort wants to use it to gain ultimate power, and the heroes from both universes have to come together to protect it. For example, Cloud Strife could join forces with Harry and his friends. The Hogwarts houses could be compared to the different classes in Final Fantasy, like Gryffindor being similar to the Warriors in Final Fantasy.
Well, a really cool plot could be that the Mass Effect Relay network somehow gets connected to the Crystal Materia in Final Fantasy. This causes chaos as both universes start to blend. Characters from both sides have to figure out how to separate the two worlds again. Along the way, they discover that there are ancient forces at work in both universes that are related. Tali could use her engineering skills to help repair some of the damaged Crystal Materia, while Squall could teach her some sword - fighting techniques from his Gunblade.
One idea could be a crossover with 'Rick and Morty'. Gary could team up with Rick and they'd have some wild adventures across different dimensions. Maybe they'd encounter some new alien species together that are a combination of the creatures from both shows.
One idea could be a crossover with Street Fighter. Imagine the characters from Final Fight teaming up with Ryu and Ken to fight a new, powerful villain that threatens both their worlds. The different fighting styles would create really cool battle scenes.
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.
A crossover with Stargate SG - 1 could also be fascinating. The Goa'uld and the Taelons both have an interest in power and domination. The SGC could get involved when they notice the Taelons' activities on Earth. They might try to figure out if the Taelons are another alien race like the Goa'uld or something entirely different.