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.
A cool plot could be that the Forbidden Forest in Harry Potter is somehow connected to a mysterious forest in Final Fantasy. Strange creatures from both forests start to interact in a dangerous way. Hermione could use her knowledge to figure out how to stop the chaos. The characters from Final Fantasy could teach the Hogwarts students how to use different weapons and abilities, and in return, the Hogwarts students could share their knowledge of potions and magical creatures.
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.
In 'Harry Potter Final Fantasy 7 Crossover Fanfiction', there are many potential concepts. One is the idea of the different races in Final Fantasy 7, like the Cetra, interacting with the magical creatures in Harry Potter. How would a Cetra view a Hippogriff? And what if the Death Eaters were after the power of the Jenova Cells? It would create a whole new dynamic of power struggles and alliances between the two universes.
One interesting plot idea could be that Fem Harry Potter is transported into the world of Final Fantasy. She could use her magic in ways that are unexpected in that world and have to learn to adapt to the new rules and technologies. For example, her spells might interact strangely with the materia system in Final Fantasy VII.
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 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 plot is that Fem Harry is a hybrid of a human and a Final Fantasy creature. This makes her an outcast in both worlds. She then embarks on a journey to find a place where she truly belongs. Along the way, she meets a group of rebels in the Final Fantasy world who are fighting against an oppressive regime. Her skills and courage make her a valuable asset to the group, and together they strive to change the world for the better.
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 to have Harry Potter characters enter the world of Final Fantasy VII. For example, Harry could end up in Midgar and meet Cloud. They could team up to fight against the dark forces in both their worlds, like Voldemort's minions and Sephiroth. The magic from the Harry Potter universe could interact in interesting ways with the materia and summons of Final Fantasy VII.
Well, there could be a story where a powerful dark magic object from the wizarding world is brought to Sunnydale. Buffy discovers it and realizes it has the power to disrupt the balance between good and evil in her world. She then travels to Hogwarts to seek help from Harry Potter. Along the way, she meets various magical creatures and has to navigate the wizarding world's politics. Once she meets Harry, they discover that there is a common enemy behind all this, someone who wants to use the chaos in both worlds for their own gain, and they must work together to stop this mastermind.
One idea could be a time - travel plot where a character from Legacies goes back in time to the era of Harry Potter. They could interact with the young Harry and his friends, and perhaps help in the fight against Voldemort in unexpected ways. For example, they might introduce a new spell from the future that gives the Order of the Phoenix an edge.