OVA
Description
Alastor, the Flame of Heaven, serves as the Crimson Realm's God of Retribution, presiding over judgment and condemnation. Bound to the Flame Haze Shana through the Divine Vessel Cocytus—a pendant manifesting as a black sphere encased by crossing gold rings—he assumes a true form resembling a massive, flame-shrouded minotaur. Wings like the night sky unfold from his back, his burning eyes pierce the darkness, and his voice echoes like distant thunder.

Initially mirroring Shana's indifference, Alastor viewed humans and Torches as insignificant objects, expressing bafflement toward human social conventions like modesty. He developed a paternal bond with Shana, sharing tales of his previous contractor and lover, Mathilde Saint-Omer. Her sacrifice during the Great War, summoning him via the Tenpa Jōsai ritual, became a turning point, driving his centuries-long search alongside Wilhelmina Carmel and Merihim for a "pure Flame Haze" dedicated solely to their mission. After numerous failures, Shana emerged as the ideal vessel.

Alastor acted as Shana's disciplinarian and mentor, though he acknowledged a critical oversight in failing to teach her social graces. His protective nature flared when Shana suffered severe injury; he annihilated Friagne in his true form and later vowed vengeance against Bal Masqué for any harm to her. During the Second Great War, he supported Shana's opposition to Yuji Sakai's plans for Xanadu, rejecting Yuji's self-sacrificial philosophy and aiding in overpowering him. Following Yuji's transformation into a "solid existence" via the Reiji Maigo, Alastor departed with Shana and Yuji to Xanadu, seeking human-Denizen coexistence.

In comedic spin-offs, Alastor exhibited misunderstandings of human relationships, mistakenly informing Shana that movies were venues for couples to fall in love and reacting with dismay upon witnessing Yuji in a compromising position with Kazumi Yoshida during a screening. His character evolved from regal detachment to a reluctant tolerance of Yuji's presence, reflecting Shana's emotional growth. While maintaining a critical view of Yuji's combat skills, he gradually accepted Shana's autonomy, refraining from excessive intervention yet remaining her steadfast guardian.