Another possibility is that Harry Potter, after the defeat of Voldemort, discovers a portal to the world of the Mikaelsons. Elijah could take Harry under his wing, teaching him about the different kind of power dynamics in his world. They could form an unlikely alliance to face a new common enemy that is threatening both the wizarding world and the world of vampires and werewolves.
A fanfiction could also be centered around a spell gone wrong that binds Harry and Elijah's fates together. They have to work together to break the spell, all while dealing with their own personal issues. Harry has to come to terms with his newfound connection to a vampire and Elijah has to adjust to the strange magic of the wizarding world.
One idea could be a crossover where Elijah Mikaelson ends up in the wizarding world of Harry Potter. Maybe he's there to seek a powerful magical artifact that could help him in his vampire family's never - ending power struggles. He might initially be seen as a threat by the Ministry of Magic but then prove himself useful in the fight against dark wizards.
A fanfiction could also be about a time - traveling scenario. Elijah Mikaelson travels back in time to the era of the founders of Hogwarts. He gets involved in the early magical society and later crosses paths with a young ancestor of Harry Potter. Their interactions shape the future of both the wizarding world and the Mikaelson family in some unexpected ways.
I really like 'Mystical Alliances' in the 'Harry Potter Elijah Mikaelson' fanfiction genre. It delves deep into the personalities of the characters. For example, Elijah's sense of honor and Harry's determination are well - explored. The author does an amazing job of creating a believable scenario where the two worlds collide, and there are some really exciting action scenes and magical duels.
To write a good 'Harry Potter Elijah Mikaelson' fanfiction, focus on character development. Since you're bringing two different sets of characters together, show how they grow and change as a result of their interactions. For instance, Elijah might learn something new about loyalty from Harry, and Harry could gain a new perspective on power from Elijah. Also, create a vivid setting that combines the elements of Hogwarts and the Mikaelson's home. Add in some exciting conflicts and resolutions, like a battle against a common enemy that only they can defeat together.
One idea could be a story where Bella discovers the world of the Mikaelsons after being turned into a vampire. She crosses paths with Elijah and they form an unlikely alliance to deal with a common threat in the supernatural world. They learn from each other's experiences, with Bella's knowledge of the Volturi and Elijah's centuries - old wisdom.
It could work by having a magical event that blurs the boundaries between their two worlds. For example, a powerful spell gone wrong could open a portal between the wizarding world and the world of the vampires. Elijah, being curious and always looking for new things, would be drawn to this new world. He and Harry would then meet and their different skills and personalities would create interesting storylines.
One idea could be that Fluttershy somehow gets transported into the Harry Potter world. Maybe she arrives at Hogwarts as a new kind of magical creature that the students have never seen before. Her gentle nature might initially cause confusion among the more rowdy students, but she could gradually make friends with the likes of Luna Lovegood, who would be intrigued by her uniqueness.
Another concept could be that Harry Potter discovers he has a connection to Magneto's mutant powers. This might happen during a strange encounter with a dark magic object that unlocks a latent power within him. He then has to learn how to control these new abilities while also dealing with the threats in his own wizarding world, and he might seek out Magneto for guidance in a secret meeting across the boundaries of their two worlds.
One idea could be a crossover where Kakashi is summoned to the Harry Potter world by a dark magic spell gone wrong. He then uses his ninja skills and Sharingan to navigate the wizarding world, perhaps even teaching some Defense Against the Dark Arts classes with his unique combat knowledge.
Maybe in a fanfiction, Harry Potter and his friends accidentally stumble upon a hidden Cybertronian relic. This relic has some sort of power that attracts Megatron. Harry and his friends then have to defend the relic from Megatron while also trying to figure out what it does and how to use it to their advantage in the fight against Voldemort.
One idea could be a crossover where Harry Potter accidentally travels to the One Piece world and meets Whitebeard. He could learn about their different forms of magic and power, and together they face a new threat that combines the dark magic from his world and the powerful pirates in the One Piece world.