Harry Potter is Sci-Fi
I would like to release billions of self replicating nanobots into the world. These bots can be controlled by ones mind, but it takes years of practice, study and focus to control them, and only certain people know about this. To help control the bots people use “augmentation” sticks that you hold in your hand and that helps you focus and control the bots around you.
These bots can do what ever you imagine, move objects, create heat, cold, electricity. They can combine like any organic or inorganic molecule so you could essentially create what ever you desire if you have the focus and understanding to do so.
This level of technology would also allow the bots to disassemble you body particle by particle and move your self, “digitally” anywhere in the world as fast as the speed of light. Essentially transporting you from one place to another.
Then I would then build a school in England where little children go to learn how to control and focus these bots and have crazy adventures.
What I’m trying to say is, Harry Potter isn’t fantasy, its Science Fiction.