You Call This a Dark Wizard Who Can Communicate with the Dead?

Leon Cromwell traveled through time, and before he could figure out the situation, he was thrown into Azkaban by the Ministry of Magic for "illegal manipulation of the undead." Faced with being surrounded by dementors, he just politely said hello to the oldest ghosts in the prison. The next second, hundreds of ghosts walked in the night, and the dementors retreated one after another! Dumbledore: "Come to Hogwarts and be a professor, kid, you are needed here." Since then, the history of magic class at Hogwarts has completely changed. Professor Binns' hypnotic magic sound? Doesn't exist! In Lyon's class, all the ghosts of historical witnesses appeared and gave their own opinions! Snape: "You liar who plays with souls!" Malfoy: "My father says you're a dangerous man!" Voldemort: "Join me, and we will rule life and death together!" In response, Leon just sighed and silently summoned the shadow raven behind him. "Sorry, I'm not interested in controlling life and death. I'm just... A porter of history." This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.