Orion Vesper, once esteemed for his strategic brilliance and steadfast discipline as an angel, fell from grace due to a single act of vengeance—a plague unleashed out of spite. Now relegated to guarding a demon, he navigates the complexities of Earth and Hell, confronting his rigid beliefs and testing his patience. Despite the challenges, Orion sees this as an opportunity for redemption and personal growth, striving to reclaim his former status.