One idea could be that Harry and Edward find themselves in a magical realm together where they have to solve a series of puzzles to save their world. They could use their unique skills, Harry's magic from his wizarding world and Edward's vampire abilities.
Another plot could be that they are both transported to a parallel universe where the rules are different. They have to adapt quickly and figure out how to get back to their own worlds, all while learning from each other's strengths and weaknesses.
One idea could be that Harry and Edward meet in a magical forest that exists between the wizarding world and the vampire realm. They initially mistrust each other but then find out they have a common enemy and have to team up to defeat it.
One idea could be that Edward, with his vampire abilities, ends up at Hogwarts. Maybe he's initially mistaken for a dark creature but then uses his skills to help Harry in a battle against Voldemort. For example, his super speed could be useful in a chase or his mind - reading ability to outwit the Death Eaters.
One plot idea could be that Jacob and Edward have to team up to protect their shared territory from a new threat. They start off distrusting each other but as they face challenges, they learn to respect and rely on one another.
Maybe there's a plot where a spell in the Harry Potter world goes wrong and somehow transports Edward into Hogwarts during a Muggle Studies class. Harry has to figure out how to send him back while also dealing with the chaos that Edward's presence causes among the students, especially the female ones who are attracted to him.
In a fanfiction, Fem Harry Potter might be a student at Hogwarts when there is an unexpected portal that opens to the Twilight world. She steps through and meets Edward Cullen. They are drawn to each other in a strange way. Edward is fascinated by her magic, and Harry is curious about his vampire abilities. They end up on a journey together, exploring both the magical and vampiric landscapes. Along the way, they face challenges like jealous vampires in Edward's coven and some wizards who don't approve of Harry's new friendship, which tests their relationship.
One plot idea could be that Alucard and Edward are forced to fight due to a misunderstanding. Maybe a powerful, mysterious force is manipulating events behind the scenes, making each think the other is a threat to their world. Another could be a battle for a powerful, ancient artifact that both believe they should possess for different reasons.
One plot idea could be that Jim discovers Edward's hidden talent for creating beautiful ice sculptures. He initially wants to use it for his own gain at a local fair but then realizes how much it means to Edward and they form an unlikely friendship.
One plot idea could be that Edward and Eren discover they are brothers in a world where alchemy and Titans co - exist. They have to combine their skills, Edward's alchemy and Eren's Titan - shifting ability, to fight a common enemy that threatens both their worlds. Another idea is that they grow up together in a small village, unaware of their special powers at first. As they start to uncover their abilities, they face discrimination from the villagers but support each other through it all.
Another plot could involve Edward making new friends in the town. These friends could be outcasts like him, and together they form a sort of club. They could then work on projects to beautify the outskirts of the town that have been neglected.
One common plot idea is exploring his past more in - depth, like his time at the military academy. It could show his relationships with other students and how he developed his skills and personality.