OVA
Description
Natsuki Minamiya balances dual roles as an English instructor at Saikai Academy and a formidable attack mage titled the "Witch of the Void." Charged with safeguarding a mystical prison holding dangerous supernatural criminals, her true body remains permanently confined within its depths, while an illusory projection interacts with the outside world—a truth uncovered during the Labyrinth of the Blue Witch arc. As the prison’s guardian, embodying the roles of jailer, door, and key, her survival is critical; her demise would unleash every imprisoned entity.

A decade-long enchanted sleep halted her aging, granting her a childlike appearance contrasted by a taller, more mature form within the prison barrier. She favors intricate gothic lolita fashion paired with a black parasol, though she adopts a school uniform for covert operations.

Beneath her stubborn exterior lies a compassionate core, evident in her efforts to nurture emotional growth in others, such as arranging outings for Astarte. While she playfully teases peers like Kojou Akatsuki, she upholds a stern professionalism in her duties as educator and protector.

The Banquet of the Observers arc sees her memories and powers stolen by Aya Tokoyogi, leaving her stranded near the Keystone Gate under the temporary alias "Sana" after being discovered by Asagi Aiba. Consuming Kojou’s blood not only restores her abilities but also summons Rain Gold, her golden-armored guardian entity, whose true strength stays sealed to avoid widespread destruction.

Mastery over spatial manipulation allows her to teleport, traverse time, and conjure magical chains or illusions. Within her specialized dimension, she wields a colossal sword and generates destructive shock waves. A tactically brilliant combatant, she leverages agility and intellect to overwhelm opponents.

Her past ties to Gajou Akatsuki, Kojou’s adoptive father, led to her guardianship over his children. Driven by a vision of harmony, she strives to bridge the divide between humans and demons, positioning herself as a pivotal mediator in the series’ conflicts.