Hermione is often a popular crossover character. Her intelligence and magical knowledge make her a great fit in the Charmed universe. She can easily adapt to new magical situations and offer her unique perspective.
One possible plot could be that the Halliwell sisters from 'Charmed' somehow get transported to the wizarding world of 'Harry Potter'. They could use their powers to help Harry and his friends in a battle against Voldemort. For example, Piper could freeze Death Eaters with her time - stopping power, while Phoebe could use her premonition power to foresee Voldemort's next moves.
One idea could be that the Halliwell sisters from Charmed visit Hogwarts. They could help the students learn some new types of magic that are more in line with their own brand of magic. For example, teaching them how to create protection spells that are more intuitive rather than formula - based like some Hogwarts spells.
There could be a really interesting fanfiction where the magical worlds of Charmed and Harry Potter collide with Harry and Maggie. Maybe they team up to fight a new kind of dark magic that threatens both their realms. They could each bring their unique magical abilities to the table. Harry with his wizardry from Hogwarts and Maggie with her powers as a Charmed one.
Hermione and Piper. Hermione is known for her intelligence and vast knowledge of magic, while Piper has the power of freezing time. They could combine their skills in a really interesting way. Hermione could research how Piper's power works and Piper could teach Hermione some time - manipulation spells that are different from what she's used to at Hogwarts.
One common theme is the exploration of different magical powers. Since both universes have their own unique magical elements, fanfictions often focus on how these powers interact. For example, the spell - casting in Harry Potter and the power of three in Charmed.
Well, they might meet in a magical crossroads. Harry could be on a mission related to the wizarding world and Maggie could be dealing with a demon in her Charmed world. And they just happen to cross paths. They'd be initially confused but then intrigued by each other's powers.
I think Hermione and Piper would make an interesting pair. Hermione is highly intelligent and book - smart, while Piper is street - smart and has her unique time - related powers. They could learn a lot from each other. Hermione could teach Piper about the complex magical theories of the 'Harry Potter' world, and Piper could show Hermione how to use her power more intuitively in real - life situations.
One interesting crossover could be the use of spells. For example, a Charmed one might learn a spell from the Harry Potter world like the Patronus charm. It could be used in a new and different way in the Charmed universe, perhaps to fight a new type of demon that is vulnerable to positive magic like a Patronus.
Often, in such fanfiction, new original characters are introduced. They could be the ones who created the charmed lemon in the first place. But it's also possible that characters like Dumbledore could play a significant role. He might know more about the charmed lemon than he lets on and be guiding the other characters from behind the scenes. Neville could also be a main character, using his skills with plants to take care of the charmed lemon or study it.