Mr Monster

A serial killer's alter-ego (Mr. Monster) and a demon-hunting FBI agent are the central antagonists/foils, and the plot is driven by a murder investigation and a supernatural conspiracy, so urban-fantasy and paranormal-romance (the slow-burn relationship with Brooke) fit alongside the core horror/thriller genres. Moods reflect the constant tension of the killer's presence, the dark humor of John's internal monologue, and the eerie atmosphere of the supernatural elements. Tropes: a literal alter-ego/darker side (Mr. Monster) is a classic anti-hero trope; the investigation-driven plot with a ticking clock and a hidden threat is a mystery box; the slow-burn romance with Brooke is a slow-burn; the mentor/protege dynamic between John and Agent Forman fits the mentor figure.