One idea could be a magical competition between Hogwarts and Cackle's Academy. Students from both schools could compete in various magical tasks, like a complex potion - making duel or a dangerous magical creature taming challenge. This would bring together the worlds of Harry Potter and The Worst Witch in a really exciting way.
Well, a plot could revolve around the witches going on an exchange program to a different, more modern magical school. This would lead to all kinds of cultural clashes and new friendships. Or perhaps a story where the teachers at the Worst Witch academy get turned into students for a day by a misfired spell, and Mildred and her friends have to teach them how to be proper students. A third idea could be that Mildred finds a magical creature that is lost and has to return it to its home, which is in a very dangerous and mysterious part of the magical world.
A plot could involve a group of witch hunters infiltrating Hogwarts. They think there are dark witches there, but they end up getting lost in the magical castle and start to see the beauty and positive aspects of magic. As they interact with students and teachers, they have to re - evaluate their views on witches and magic in general.
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.
One idea could be that the Witch OC is a transfer student from a far - off magical school. She has unique magical abilities that are rare in Hogwarts, like the ability to communicate with magical creatures on a deeper level. This could lead to her helping Hagrid with some of his more difficult creature - related tasks and catching the attention of Harry and his friends.
Maybe the Scarlet Witch travels back in time to the era of Harry Potter. She could end up at Hogwarts and teach the students some new magic based on her powers. The students, especially Harry, would be fascinated by her different style of magic. They could team up to protect the school from an ancient evil that is awakened by her arrival in the past.
One plot idea could be that the vampire witch reader is initially seen as a threat at Hogwarts. But as Harry Potter gets to know her, he realizes she's not all bad. She might be hiding her vampire nature because she fears persecution. They could team up to fight against some dark forces that are using vampire magic in a wrong way.
A fanfiction could explore what would happen if the magic from the Harry Potter universe was somehow combined with the powers of the Last Witch Hunter. For example, the Last Witch Hunter could gain the ability to use spells like Harry Potter, or Harry could get some of the unique skills of the Witch Hunter. This would lead to a whole new set of adventures and challenges for them both.
A great plot might involve the worst witch losing all her magical abilities due to a powerful curse. However, instead of being discouraged, she decides to start from scratch and learn non - traditional forms of magic. Along the way, she uncovers secrets about the origin of magic itself and uses this knowledge to not only regain her powers but also to become a more respected and powerful witch in a completely new way.
A great plot for a Potter Manor fanfiction could involve a mystery that surrounds the manor. For instance, strange noises at night lead Harry to uncover a long - forgotten chamber. It could also be about Harry restoring the manor to its former glory, perhaps with the help of Hermione's research on ancient magic used in the construction of such manors.
One idea could be that the main character discovers they have magical powers that are different from the witch's. For example, they can control time in a unique way while the witch mainly deals with nature magic. Another plot could involve the main character being adopted into a witch family and having to learn their ways to fit in, like attending a magical school for witches and warlocks where they face challenges from other students who are skeptical of an outsider joining. Also, perhaps the main character is adopted by the witch to fulfill a prophecy, and they have to figure out what that prophecy means and how to fulfill it while dealing with the normal struggles of growing up in a magical world.