Ilias Fragment

Ilias Fragment, is a grimoire that was owned by Hijiri. In human form, she goes by the name of Ilya.

Personality
Compared to Astil Manuscript, aka Sora, Ilya is much more modest at heart, preferring to show the straight man to Arata's antics like Lilith and Mira. On the other hand, she is incredibly possessive of him, to the point of setting up a very elaborate trap dimension to imprison him and keep him with her, as well as showing him rather immodest visions of how she can make that life for him. She's rather embarrassed however when this is brought up.

When first introduced she acted somewhat like a Yandere towards Arata, but has since mellowed out.

History
She was previously the second of Hijiri's Grimoire and would often take her place when she was out on duty, thus taking care of Arata.

She seemed to remain with Hijiri, eventually being sent to detain Arata in the sealed dimension containing Liber Academy. She was largely successful in this, successfully trapping Arata in her dimension, but also for some reason Mira. When her plans reach the point of killing Sora and Mira, Arata's anger transforms him into Astral Trinity, who proceeds to utterly unravel everything she'd set up and destroy her dimension with a Breakdown Phenomenon.

After Astral Trinity was contained, Arata thanked Ilya for all the times she'd taken care of him and proceeded to ask her to get them out of the dimension, which she cannot do due to the interference of Astral Trinity's Breakdown Phenomenon. After destroying the Breakdown Phenomenon however, Arata's group is transported home, along with her as his second Grimoire.

Powers and Abilities
She is not as powerful as Astil Manuscript in terms of raw power, as she readily admits, but she is shown to be both craftier than Sora and more level headed, to the point of even defeating her with these traits quite easily.

As a Grimoire, she is capable of controlling the spectres in the dimension she was placed to bind Arata, and can move freely despite its restrictions on magic, she also had the ability to cast protective barriers which, while unable to fully block Mira's attacks, held their own long enough for her to get away.

She is a support type Grimoire, thus her function in battle allows her to stabilize her master's magic, as well as compensate for any additional power that might harm him/her.