Episode 4 — Devils Line

Reviewers from sites like Moe Sucks and Anime News Network highlight the episode's dark exploration of bloodlust and human morality:

: As Anzai goes out of control, a new character— Hans Lee , a white-haired half-devil—intervenes. Unlike Anzai, Hans has developed a tolerance by consuming small amounts of blood regularly, allowing him to maintain his sanity while in a transformed state.

: The police eventually sedate Anzai. Two weeks pass without Tsukasa hearing from him, leading her to search for him in the area they last met. Instead, she finds Hans, who explains the nature of "oni" (devils) and offers hope that Anzai can eventually overcome his weaknesses. Critical Analysis and Themes Devils Line Episode 4

: Amidst the chaos, the anti-devil sniper Zero Seven (Nanako Tenjo) attempts to kill both Anzai and Hans. Tsukasa puts herself in direct danger by trying to shield Anzai from the sniper's line of fire, showcasing her growing, albeit reckless, dedication to him.

: The episode underscores a recurring theme where the "monsters" are often more sympathetic than the humans hunting them. For example, Zero Seven’s trauma—her mother was killed by a devil—fuels a vengeful crusade that leads her to shoot indiscriminately. Reviewers from sites like Moe Sucks and Anime

: The title "Monster" refers not just to Anzai's physical transformation but to the internal struggle of maintaining one's humanity when biology demands violence.

The episode picks up with the aftermath of Anzai consuming human blood. While intended to heal his wounds, the blood triggers a violent frenzy because Anzai, as a hybrid with no built-in tolerance for human blood, cannot control the resulting narcotics-like high. Two weeks pass without Tsukasa hearing from him,

: The relationship between Tsukasa and Anzai is often critiqued by fans on Reddit for being rushed or "cringe," yet others find it a compelling, "hot-and-cold" emotional roller coaster that avoids the typical "sparkling vampire" tropes. Adaptation Notes