One possible plot is that Voldemort somehow has a connection to an Asgardian villain. Harry, being the hero, travels to Asgard to find a way to defeat Voldemort once and for all. Along the way, he meets the Asgardian gods. They initially doubt him but soon realize his strength. Harry then combines his wizardry with Asgardian magic to face the dual threats of Voldemort and the Asgardian foe.
Harry could be seen as a strange but powerful being. His Gryffindor courage would be respected in Asgard. Hermione might be seen as a great scholar, like the Asgardian mages. Ron could be the loyal friend who has to adapt to the grandeur of Asgard.
One interesting plot idea is when the magic systems of Asgard and Hogwarts collide. For example, the use of seiðr (Asgardian magic) in the wizarding world of Harry Potter. Another is characters from Asgard attending Hogwarts. Imagine Loki causing chaos in the halls of Hogwarts or Thor trying to fit in with the wizards.
A Harry Potter and Asgardian fanfiction could be really exciting. It might involve Harry Potter being magically transported to Asgard. There, he could learn about the Asgardian magic and culture. Maybe he would meet Thor and they would go on an adventure together to fight some dark force that threatens both the wizarding world and Asgard.
A plot could revolve around a prophecy that involves both the wizarding world and Asgard. Harry is the key figure in the prophecy. He travels to Asgard to find out more. There, he meets Odin who initially distrusts him. But as Harry proves his worth through his magical abilities and courage, Odin decides to help him. Together, they must face a common enemy that is emerging due to a dark magic that is seeping between the two worlds. Harry could also form a friendship with Sif, who teaches him some Asgardian fighting techniques.
The fanfic could center around Harry's life outside of the main events of the books. For example, it could explore his summer holidays in more detail. He could be spending time in the Muggle world and using his magic in creative ways to solve normal, everyday problems. He might use magic to help his neighbor fix a broken fence without the neighbor realizing it was magic. This would add a new dimension to his character and show how he can adapt his magical abilities to different situations.
One possible plot could be that Harry Potter is hired by Sherlock Holmes to help with a case that involves dark magic. Harry uses his knowledge of the wizarding world to uncover clues that Sherlock couldn't find with just his deductive skills.
Imagine Harry Potter as a bartender. He could be using his skills not just in mixing drinks but also in reading people. Since he has faced so many challenges in his life, he can easily spot if a customer is hiding something or if they are in trouble. His bar could become a place where secrets are shared, and he has to use his wits and magic to keep things in order. He might also have to deal with rival bartenders from other wizarding establishments who are jealous of his popularity and unique drinks.
The plot could involve Harry Potter discovering he has some sort of connection to a dragoness. Maybe he can communicate with her telepathically. They could team up to fight against dark forces in the wizarding world. For example, Voldemort might be after the dragoness for her powerful magic, and Harry has to protect her while also using her strength to defeat Voldemort.
One possible plot could be a deaf Muggle - born student getting their Hogwarts letter. They face difficulties in the beginning as they can't hear the instructions well. But they soon discover a magical device that helps them 'hear' in a magical way, like through vibrations that translate into words in their mind. Then they go on to prove themselves in classes like Charms and Potions, making friends along the way.
Well, it could be that Harry discovers a hidden chamber in Hogwarts that has Xenomorphs in it. Maybe he has to use his magic to fight them off or find a way to co - exist.