One interesting plot could be the phantom having a hidden past related to an ancient Hogwarts mystery. Maybe it was once a powerful wizard who was wronged and now haunts the school for revenge or to right a wrong.
One interesting plot could be how the pregnant character manages to keep up with their studies at Hogwarts while dealing with the physical and emotional changes. Maybe they have to hide it from some strict professors.
One interesting plot could be the phantom's hidden past. Maybe it reveals that the phantom was once a normal student who was wronged and turned into a phantom. Another plot could be the phantom's relationship with a particular character, like a friendship or a rivalry that develops in unexpected ways.
Another plot could involve her struggle to fit in with normal society while having this extraordinary phantom - related background. She may face discrimination or misunderstanding from others, but in the end, she manages to find a group of people who accept her for who she is.
One possible plot could be that Danny is kidnapped by a new ghost enemy who wants to use his powers for their own evil deeds. Maybe this enemy plans to drain Danny's ghostly energy to become more powerful. Another plot could involve Danny being kidnapped by a group of his human enemies who have finally discovered his secret identity and want to experiment on him. Or perhaps a time - traveling villain kidnaps Danny to prevent him from ever becoming a hero in the future.
Maybe there's also an old Hogwarts professor who has some knowledge about the phantom's existence. This professor could play a crucial role in guiding the students or trying to solve the mystery related to the phantom.
One interesting plot could be Harry becoming an Auror and facing new dark wizards that emerge post - Hogwarts. He uses his skills learned at Hogwarts to protect the wizarding world in a more complex and dangerous environment.
A really interesting plot is when the magic from Hogwarts and the powers of the demigods in Percy Jackson's world start to mix in unexpected ways. For example, in some fanfictions, the spells start to work differently around demigods, creating all sorts of chaos and new adventures. It's fascinating to see how the two different systems of magic interact.
One interesting plot could be Albus making unexpected friends on the Hogwarts Express. Maybe he meets a shy first - year who has a unique magical ability that Albus has never seen before. They then form a bond and face challenges together at Hogwarts.
There could be a plot where Harry's upbringing at Hogwarts affects his relationship with the other students. He might be seen as an insider by some, but also an oddity by others. This could lead to some interesting dynamics, such as rivalries or unexpected friendships. For example, he might have a closer friendship with the students from different houses as he doesn't have the same house - based prejudices that other students have.
One interesting plot could be Hermione's growing friendships. She might form closer bonds with some characters that were just acquaintances in the original story. For example, she could become really good friends with Neville and help him gain more confidence in his magical abilities.