His Majesty the King of Hogwarts

Edmund Pevensie was transported to Hogwarts in 1991 by a trumpet sound that only he heard. He has been the king of Narnia for 15 years, but now he can only find the mysterious man who blew the trumpet while becoming a student again. Hogwarts was beautiful, but he soon discovered that there were some corners where the light of magic could not penetrate. It was never just the Dark Lord lurking in the shadows. (PS: Readers who don't know "The Chronicles of Narnia" and "Harry Potter" can also read it easily)