Maybe in the fanfiction, Aunt Lemon has a hidden magical past herself. So when Harry comes to live with her, she starts to teach him some ancient spells that she learned long ago. This would add an interesting layer to their relationship as they bond over magic that is different from what Harry learns at Hogwarts.
One idea could be that Aunt Marge accidentally eats a lemon - flavored magical treat that makes her temporarily nice to Harry. For example, she might start complimenting his schoolwork at Hogwarts instead of her usual mean - spirited remarks.
One plot idea could be that Aunt May discovers Spider - Man's identity in a very emotional moment. Maybe she stumbles upon his suit while cleaning his room. Then, instead of being angry, she becomes his confidant and helps him with his superhero duties in a more hands - on way, like creating special first - aid kits for his battles.
Perhaps in the fanfiction, Vernon discovers a hidden magical talent of his own. Harry, upon finding out, has to decide whether to help Vernon develop it or keep it a secret from the wizarding world as Vernon is a Muggle. This could lead to a lot of comical and tense situations.
Perhaps in a Hogwarts where the normal rules are a bit more lax for a short time. Harry accidentally stumbles into Trelawney's classroom during one of her more intense divination sessions. She mistakes his presence as a sign from the stars. This leads to them spending more time together, and gradually feelings develop. They might go on a secret adventure within the castle grounds, exploring hidden chambers while their relationship blossoms.
Perhaps Loki and Harry find themselves in a situation where they have to swap powers for a day. Loki has to deal with Harry's magic wand and spells, while Harry has to handle Loki's shape - shifting and illusions. This could lead to a series of comical and also character - building moments as they learn from each other.
One idea could be a time - travel plot where Harry goes back in time and McGonagall is much younger. They form an unexpected bond during a dangerous situation at Hogwarts that gradually turns into a deeper, more romantic relationship. But they have to keep it a secret due to the age difference and the rules of the wizarding world.
A possible plot could be that Harry and Nagin are both chosen for a special task in the wizarding world. They initially clash due to their different personalities but gradually learn to work together and form a strong bond along the way.
Maybe Harry and Amelia are from two different worlds. Harry is from a world of magic and Amelia from a non - magical world. They accidentally cross paths when a magical portal opens up. They then have to learn about each other's worlds and help each other out in various situations, such as Amelia helping Harry understand non - magical technology and Harry showing Amelia the wonders of magic.
One possible plot line could be Aunt Petunia having a change of heart towards Harry due to some magical event in the fanfiction. Maybe she discovers a hidden side of magic that makes her see Harry in a new light.
Perhaps Aunt Petunia is a witch who was cursed long ago. The curse made her forget her magic and act like a Muggle. When Harry unknowingly breaks the curse, she suddenly has her powers back. She then has to face the wizarding world again and deal with all the changes that have occurred since she last remembered her true self. She might even have some unique powers that are different from the norm because of the curse.