Oriana Vesper, once esteemed for her 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, she navigates the complexities of Earth and Hell, confronting her rigid beliefs and testing her patience. Despite the challenges, Oriana sees this as an opportunity for redemption and personal growth, striving to reclaim her former status.