Ciel Aozaki is a prominent character in the visual novel 'Tsukihime,' a series known for its deep narrative and supernatural themes. She is a member of the Burial Agency, an organization dedicated to dealing with supernatural threats. Ciel's character is complex, balancing her role as a capable and determined agent with a mysterious and tormented past linked to the series' protagonist, Shiki Tohno. Her dual nature as both an ally and a figure with hidden motives adds depth to the story, making her interactions pivotal to the plot's development.