Another plot could involve a family mystery. Maybe they discover a long - lost relative who has a dark secret that endangers them all. They then have to work together to uncover the truth and protect their family. It could involve researching old family records, interviewing people from their past, and facing off against those who want to keep the secret buried.
Well, Dean's protective nature would extend to his new - found brother Harry. He'd probably be a bit skeptical at first about Harry's magic but would quickly see how useful it could be. Sam, on the other hand, would be more interested in understanding the mechanics of Harry's magic and how it could fit into their world. Harry would be intrigued by Dean and Sam's hunting skills and might want to learn from them. Their different personalities would create a dynamic where they learn from each other and also clash at times. For example, Dean's quick decisions might annoy Sam when he wants to think things through more, and Harry might not always understand the urgency of some of their hunting situations at first.
One idea could be that they go back to the time when their parents first met. They could try to prevent some dark force from interfering with their relationship, which would change the course of their family's future. Another plot could be them going back to a crucial moment in the fight against a major demon, and they use their present - day knowledge to change the outcome for the better.
One idea could be that they discover their brotherhood through a magical accident. Maybe a spell goes wrong and reveals their hidden family connection. Then they have to deal with the shock and also how it will change their relationships with others at school.
Another plot could be that Harry and Neville are actually long - lost twins separated at birth. They start having strange dreams about each other and then figure out the truth. This revelation would change their relationship and how they see themselves in the wizarding world. They could then team up to face a new, powerful dark force that is emerging, using their combined skills and the new - found bond between them.
One idea could be that Bella discovers she has special powers because of her relation to Sam and Dean. Maybe she can communicate with spirits in a unique way that helps them on their hunts.
Well, it's possible that such a fanfiction exists. However, this would be a very strange crossover considering that 'Dean and Sam' are from 'Supernatural' and 'Harry' is from the 'Harry Potter' series. It might be a very niche or even a dark and edgy take on combining these two universes. But again, without a proper search on the relevant fanfiction platforms, it's difficult to say for sure.
A unique plot could be that their marriage gives them new powers. Since they are so closely bonded now as husbands, they can combine their powers in ways they couldn't before. For example, when facing a powerful demon, their united power makes them invincible.
A really cool plot might be that Fem Harry Potter accidentally transports herself to Sam Uley's world while trying out a new spell. She discovers that there are some similarities between the magic in her world and the spiritual powers in Sam's world. Sam and his pack initially view her with suspicion, but as she proves herself helpful, they start to accept her. Together, they could embark on a journey to find a way to send Harry back home, all while facing various challenges along the way, like other supernatural creatures who see Harry as an intruder or a source of power.
One idea could be exploring the early days of the Peverell brothers. Maybe show how they discovered the Deathly Hallows and what led them to their different fates. For example, Antioch's obsession with the Elder Wand and how it affected his relationships with his brothers.
One possible plot could be that Harry discovers her relation to Sam and Dean early on. She then tries to balance her wizarding education at Hogwarts with the hunting life of her brothers. Maybe she uses her magic to fight off the same demons that Sam and Dean are hunting, but in a different, more magical way.