Well, a really cool plot might be that the Hogwarts School of Witchcraft and Wizardry is somehow transported into the Star Wars universe. The students and the Jedi start to exchange knowledge. Harry Potter, being an experienced wizard, starts to learn about the Force from the Jedi masters, while Rey and the other Jedi are fascinated by magic. But then a common enemy emerges, like a Sith lord who wants to use both magic and the Force for evil, and they all have to work together to stop him.
One possible plot could be that Harry Potter, while exploring new magical realms, stumbles upon a portal that leads him to the Star Wars universe. There, he meets Rey and they discover that magic and the Force have some similarities. They could team up to fight against a new dark force that is threatening both their worlds.
A great plot for this fanfiction could be that the magic from the Harry Potter world is actually an ancient form of the Force that has been forgotten in the 'Star Wars' universe. So, a group of wizards and witches from Hogwarts, led by Ron Weasley, travel to the 'Star Wars' galaxy to teach them about magic. However, they soon find out that the Dark Side of the Force is very similar to the Dark Arts in their world, and they have to fight against it together with the Jedi and the Resistance. This would bring a whole new dynamic to both universes.
Obviously, Harry Potter and Rey could be the main characters. Harry has his skills in magic and combat against dark forces, and Rey has her connection to the Force and her combat skills. They could be the central duo, with each learning from the other.
Well, it could be about Naruto somehow being transported to the Star Wars universe of The Force Awakens. Maybe he teams up with Rey. He could use his ninja skills along with the Force, like using his chakra control to enhance his use of the Force.
Another theme is the cultural exchange. The characters from the two universes come from very different backgrounds. So, in the fanfiction, you might see how a female Harry Potter adapts to the Star Wars universe and vice versa. This could include things like how she reacts to the different social hierarchies or the technology in the Star Wars world.
I think Hermione would be the most interesting. She's highly intelligent and resourceful. In 'The Force Awakens' world, she could use her vast knowledge of magic to analyze and perhaps even enhance the technology there. She might also be able to come up with unique strategies against the First Order using her magical skills, like creating illusions to deceive the enemy or using spells to protect the Resistance bases.
In this fanfiction, it could be that the appearance of the keyblade is a sign of a greater prophecy. Harry, being the chosen one in his own world, is now also the one to awaken the keyblade. He has to face challenges like learning new combat styles, understanding the keyblade's magic which is different from his usual spells. And along the way, he might make new friends or enemies related to the keyblade's origin and purpose.
Well, he could start by trying to find a way back to his own world. But in the process, he gets involved in the affairs of Spira. He might meet some characters who are similar to his friends at Hogwarts. They could form a group and together they explore the mysteries of Spira. Harry could also share his knowledge of magic with the local wizards (if there are any), and in return, learn about the unique magic system of Spira.
There are quite a few out there. One interesting one might be on FanFiction.net. You can search for it using the tags 'fem Harry Potter' and 'The Force Awakens'. However, the quality can vary greatly, so be prepared to sift through some not - so - great ones to find the real gems.
Well, perhaps in this fanfiction, the devil gene is awakened when Harry is exposed to a powerful and cursed object. As the gene awakens, he starts to have strange visions and an uncontrollable urge for power. His Hogwarts experience completely changes as he has to deal with this new aspect of himself. He may also attract the attention of dark forces that want to use his newfound power for their own evil purposes.
One interesting plotline could be about Naruto learning new and unique jutsu from the Force. Maybe he combines his chakra with the Force in unexpected ways, like creating a new type of Rasengan infused with Force energy.