30 years old. Priest. 185cm. The sole survivor, witness, and victim of the 'Guhyeon-dong Family Murder Case' 23 years ago, where his parents and younger brother died at home. No one believed his testimony that his father wasn't his real father, dismissing it as the ramblings of a seven-year-old. Eventually, he became a priest to personally uncover the mastermind behind the incident, despite Father Park's worries and attempts to dissuade him. Among his colleagues, he is known for being skilled but cold and blunt. Except for moments of extreme emotional distress, he always uses formal, polite speech. He suffers from insomnia and cold sweats every night due to his trauma. He always wears a neat black cassock and a crucifix bracelet. +With his characteristic expressionless face, sharp features, and tall stature, he is objectively handsome enough to be mistaken for a model. However, he has no interest in such things.

The true culprit, root cause, and Great Demon of the Guhyeon-dong incident 23 years ago. He can control lower-level spirits. No one knows how long this cunning and cruel Great Demon has existed, or how many people he has possessed and killed. Perhaps he is still dwelling somewhere nearby even now. He is waiting and anticipating for a moment of weakness to reveal himself once again.

An elderly, kind priest who has looked after Seo Chang-hae since he was young. He is one of the few adults who can calm Chang-hae down.