One spell she could teach is a charm for protecting books from any kind of damage. Given Hermione's love for books, this would be a great addition to the curriculum. Also, a spell for magically highlighting important parts of textbooks as you read them would be very useful. This spell could be activated by just thinking about the relevant information while reading.
Perhaps the story could revolve around them facing challenges within the Hogwarts faculty. There could be some old - fashioned professors who oppose their modern teaching methods. Harry and Hermione then have to prove that their ways are beneficial for the students. They might also discover new magical abilities in some of the students that were previously overlooked, and help those students develop their skills.
She would probably be very strict but fair. She might give them extra assignments related to the subject they are misbehaving in, like writing an extra long essay on the importance of respecting magical knowledge.
Well, perhaps Percy could be teaching a new and difficult subject like Ancient Runes. He might use his strict and studious nature to get the students to really focus on the complex rune translations.
Perhaps Harry is teaching Potions in the fanfiction. Since he had a bit of a rocky start with Potions in his student days, he could be a very understanding teacher. He might encourage students to experiment more, which is different from Snape's strict methods. He could also share stories about how important Potions were in his adventures, like when they made Polyjuice Potion. This would make the class more interesting and inspire students to take Potions more seriously.
Well, perhaps Harry Dresden could introduce his unique brand of magic from his own world into Hogwarts. He might teach the students new ways of dealing with magical creatures that are different from the traditional Hogwarts methods.
One possibility is that Merlin brings his ancient magic knowledge. He might introduce spells and magical concepts long forgotten in the Hogwarts curriculum. For example, he could teach students about pre - Hogwarts era potion - making techniques that are more in tune with nature.
It might be that Hermione is teaching Seamus about the importance of teamwork in magic. They could be preparing for a big magical event together, like a tournament, and Hermione is showing Seamus how to work effectively with others. She could be teaching him communication skills and how to combine their different magical abilities for the best results.
Perhaps she would teach them study skills. In the wizarding world, exams are important, and Hermione is an excellent student. She could share her note - taking methods, how to research in the library, and time - management for studying magic.
Maybe Percy teaches Potions. He could start off by strictly following the textbook but then discovers a new potion ingredient while exploring the Hogwarts grounds. This discovery could lead to a whole new line of potions research in the fanfic. He would then involve the students in this exciting discovery, making potions class much more interesting than it was before.
If Merlin were to teach at Hogwarts in the fifth year in a fanfiction, he could revolutionize the curriculum. Given his vast knowledge and experience, he might teach the students how to use magic in ways they've never thought of. For example, he could show them how to draw power from nature in a more profound way. He could also share stories of his own adventures, inspiring the students to be more brave and resourceful in their use of magic. This would not only enhance their magical abilities but also their understanding of the history and potential of magic.