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.
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.
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.
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 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.
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.
If Edward Elric taught at Hogwarts, it would be a wild ride. He's used to a different magical system in his own world. He could bring in concepts like equivalent exchange to the Hogwarts curriculum. His experience with his own dark and dangerous adventures would give his teaching a sense of urgency and real - world applicability that Hogwarts students might not be used to. He might have some clashes with the more traditional Hogwarts professors at first, but eventually, they'd see the value in his different perspective.
Well, he might show off some really old - fashioned but extremely powerful magic that would shock everyone at Hogwarts. Maybe he'd befriend Harry Potter and teach him some ancient spells that could defeat Voldemort in a whole new way.
In a 'Merlin and Arthur at Hogwarts' fanfiction, the story could start with Merlin accidentally casting a spell that sends them both to Hogwarts. At Hogwarts, Arthur is amazed by the magical creatures and the Quidditch games. Merlin tries to blend in but his unique abilities make it difficult. They both get caught up in a mystery within the school, like a hidden chamber that holds a powerful and ancient magic. As they explore, they discover that their fates are somehow linked to the history of Hogwarts, and they must use their combined skills - Arthur's leadership and Merlin's magic - to solve the mystery and find a way back to their own world.