Who could be the potential teachers in 'Harry Potter builds his own school fanfiction'?

Well, one possibility is that Harry Potter builds the school in a hidden location, away from the prying eyes of the Ministry of Magic. He might create a curriculum that focuses on both traditional magic and new, unique areas of study that he discovered during his adventures.

Obviously, Harry himself would be one of the main teachers. He could teach Defense Against the Dark Arts. Hermione would also be a great teacher. She could teach Transfiguration as she was excellent at it. Ron might teach something like Care of Magical Creatures. He has a lot of experience with magical creatures from their adventures.

Well, Hermione is an obvious choice as she's not only smart but also very loyal to Harry. Ginny would be there for sure, given her love for Harry. Then there could be some less - known characters like Astoria Greengrass. She might be drawn to Harry's charisma. And don't forget about Nymphadora Tonks. Although she's older, in a fanfiction world, she could develop an unexpected attraction to Harry because of his brave and selfless nature.

One possible plot could be that Harry, after all his adventures, realizes the importance of a new kind of magical education. He decides to build a school that focuses on teaching not only magic but also how to use it for good in the real world. He might gather his old friends and some new allies to help him find a location, design the curriculum, and recruit students from all over the wizarding world.

Professor McGonagall could be one of them. She is strict but fair and has a lot of knowledge about transfiguration which could be shared with Harry in a more personal way in this fanfiction.

Perhaps he barters with magical beings. He could offer his services in solving magical problems for them in exchange for rare building resources. For example, he might help a group of centaurs with a prophecy issue and in return, they give him enchanted wood or special stones. He may also get help from his friends who have access to different resources. Hermione might provide some rare books with building spells, and Ron could get some things from his family's old collection.

Well, perhaps Harry Potter decides to build a school in Italy to spread the knowledge of magic in a new region. He might face challenges like getting approval from the Italian Ministry of Magic, if there is one in the fanfic. And he would need to find suitable teachers who are familiar with both the British and Italian magical traditions.

Maybe there's a powerful and corrupt wizard in the Ministry of Magic who doesn't want Harry to have an independent means of travel like the yacht. This wizard could send his minions to disrupt Harry's work, or even create false laws that would make building the yacht illegal in the wizarding world.

The Death Eaters could be the antagonists. Even though Voldemort is gone, some of his followers might not want Harry to succeed in building a starship as they fear it could bring more power to Harry and his friends, and they still hold grudges against him.

Maybe an old wizard who has been secretly studying the combination of different magical universes for years. This wizard could have made some initial attempts at building a lightsaber - like weapon in the past and can share his experiences and mistakes with Harry. He would teach Harry about the balance between the light and dark side of this new form of magic, just like the Jedi teachings in Star Wars.