Okto

 is a younger sister of Ilia, and the Eighth Chapter of the Ilias Fragments. As the only survivor after Radix Astil's assault that killed her master, the Witch of the West, and sealed her sisters, the grimoire would eventually meet and guide Ilia and her sister's master, Arata through Dante's Gate.

Personality
Okto has a cordial and considerate disposition, caring deeply for her family's safety especially after the death of her master and capture of her sisters. Nonetheless, she continues to behave in a thorough and friendly manner when interacting with others, even once after sending demons to assault arrivals at Dante's Gate in order to evaluate their strength.

Appearance
Okto is a young slender woman with long hair, her features resembling an adolescent version of her elder sister Ilia. The grimoire typically wears a hairband and styles her hair with small pigtails. Her attire consists of a white dress worn under a long sleeve light robe with a hood.

History
Okto, along with Ilia and her sisters, manisfested after their master, the Witch of Witches gathered them to become the Chapters of the Ilias Fragments.

Broken Family
Three hundred days before Dante's Gate's opening, Okto witnessed Radix Astil's arrival who then murdered the Witch of Witches before sealing her sisters within crystals. As the last remaining Chapter, the grimoire could only wait within Dante's Gate for support in hopes of rescuing her siblings.

Hope
While bathing in a river, Okto suddenly senses her elder sister approaching Dante's Gate.

Upon Ilia and her party's arrival, Okto secretly summons an army of demons in order to evaluate her sister's Arata Kasuga's strength which he easily dispatches the leader. Impressed by the Demon Lord Candidate, the grimoire then reveals her presence, happily reuniting with Ilia who introduces her to the members of the group. Although Okto feels guilty about conjuring the army and attacking them, Arata and the others nontheless forgive her actions. Furthermore, the grimoire recognizes Arata's strength and considers him capable enough to survive within Dante's Gate. However, when Ilia questions her about the status of the remaining sisters, Okto tearfully requests that she and her master rescue them.

Later, Okto guides the party through Dante's Gate, explaining the general structure of the world, but Ilia insists that she explain their sister's situation. Okto then reveals that their sisters have been sealed within the various levels of Hell, as well as the death of their master by Radix Astil. As Arata questions Okto about Radix's reasoning, the culprit herself suddenly appears before the group and explains her motivation to use the sisters as a trial for the Demon Lord Candidate. However, Okto then witnesses Arata utilizing his magic to dominate Radix, prompting the perpetrator to retreat.

After getting separated, she was left with Akio to deal with Melacoda.

Abilities
Okto possess the ability to summon an army of demons to attack her enemies. However, if the leader is defeated, the remaining members will disappear.

Trivia

 * In Okto's first appearance, she quotes the first line of Homer's The Iliad, "Menin aeide, thea, Peleiadeo Achileos" which translates from Greek into "Sing, O goddess, the anger of Achilles son of Peleus."