Hijiri Kasuga

Hijiri Kasuga is a childhood friend and cousin of Arata who disappeared due to a Breakdown Phenomenon after giving the Astil Manuscript to him. She is later on revealed to be a magus sent by Royal Liber Academy to pose as his cousin and eventually returns as a member of Iscariot.

Personality
Hijiri is a cheerful and poised young lady, as well as a strong devotion to those close to her, especially towards Arata. Despite having been assigned as his observer, she cares deeply for his well-being, becoming more concerned of his protection than her own, and even willing to entrust Sora to him before she disappeared due to a Breakdown Phenomenon. As suggested by the opposite of her Thema Ruina, Hijiri is concerned more of others and passionately determined to protect her loved ones. After witnessing Arata's future, she became willing to fight the entire world for him, angry and unforgiving of the world using him as a means to its revival. Often saddened by her current situation, she sometimes will have small periods of extreme vulnerability, such as nearly collapsing in tears after Arata promises to bring her back. Neverthess, she remains incredibly resolute in achieving her goals.

However, Hijiri also has a very cold and ruthless side, willing to go to extremes to accomplish her objectives such as murder or even destroying the world. Surpringly, she would even attempt to kill Arata and the Trinity Seven, intending to resurrect him after her plans were accomplished. Additionally, she can be quite forceful and intimidating, once almost causing Lieselotte to hesitate in her decision to support Arata. In her initial confrontation against Anastasia-L, their tense interactions would greatly frighten Lugh and Anna's companion. During battles, Hijiri displays a calm and calculating attitude, able to confidently attack and defend against enemies. Although, she can be surprised by any unexpected developments.

While sometimes overly serious, Hijiri is usually quite calm and light hearted, once awkwardly commenting on Arata's perverted antics. Among trusted friends and allies, she is more friendly and approachable.

Appearance
Hijiri is a young slender young woman with short blue hair and a single ahoge on top of her head. She bares a striking resemblance to Arin Kannazuki, but is far more expressive of her emotions. After disappearing due to a Breakdown Phenomenon, her hair grew noticebly longer but has since returned to her original shortness. Additionally, she also has a small  hair clip on the left side of her bangs, but sometimes wears another one on the right side as well.

Prior to vanishing, Hijiri wore a sailor fuku which consisted of a white long sleeved blouse with a sailor collar, a red ribbon tie, a dark pleated skirt, dress socks and penny loafers. After returning as a member of Iscariot, she adorned a short dress under a long sleeve hooded robe, and a hair clip.

Satan: In this form, Hijiri's hair grows even longer, a crack-like mark appears on her right cheek similar to that of Astral Trinity's, and her hands transforms into large monster like claws. She also wears a headband, a long dark off-the-shoulder dress worn under a shoulderless cape held together by a brooch attached to a metallic choker, and a pair of dark slipper shoes.

History
Sometime ago, Hijiri was sent by the Royal Liber Academy to monitor Arata's development as a Magic King, under the guise of his cousin while his parents were missing for a number of years. During away missions, she would have Ilia pose as her while she was gone. One day, a Breakdown Phenomenon suddenly apeared in their hometown. During the destruction, Hijiri gave her Astil Manuscript to a bewildered and frightened Arata, asking her grimoire to protect him as well as grant his wish. After leaving him some last instructions, she kisses him and begs him not to forget her before finally vanishing. After beging engulfed, Hijiri finds herself in an empty world, but is nevertheless satisfied. However, before her consciousness fades away, she witness a future where Arata and the Trinity Seven had destroyed the entire world. Learning of the world's neverending cycle of the Magic King and Trinity Seven to destroy the world, Hijiri became unable to forgive the world for treating Arata as nothing but a tool for its reincarnation. Motivated by this feeling, she would join Iscariot in an attempt to destroy and recreate the world into one Arata could enjoy freely.

Chaotic Rune
Hijiri's Themas are Ruina, Partum, and Analysis of the Ira Archive and her branch of magic is Chaotic Rune, which is based on Norse Runes. Hijiri is a very powerful magus, being able to simulataneously contract with more than one legendary grimore, Astil Manuscript and Ilias Fragment, even before becoming a Magic King Candidate. Notably, she once mentioned that she was stronger than Arata, and was even described as Iscariot's trump card to defeat him. As a Chaotic Rune user, she has a tremendous amount of offensive power, as well as a very strong defense. On one ocassion, she remained completely unharmed after Lilith attempted a surprised attack on her. Additionally, Hijiri has demonstrated the ability to break time and space, being able to teleport far distances. She also mentioned that is able to revive someone from the dead using their magic and grimoire, once intending to bring Arata back to life some time later after killing him.

After disappearing by a Breakdown Phenomenon, Hijiri received a Magic King Element from the "Ruined World," becoming a Magic King Candidate. However, as result, she can no longer remain in the world for extended periods of time as her body had been broken down by the Breakdown Phenomenon. At present, she is an existence swaying between space and time, taking on the appearance of a gemstone similar to the Magic King Element whenever she is unable to maintain her form.

While considered as a strong magus, Hijiri's Chaotic Rune magic can be nullified by Arin's Demon Spear Gae Bolg. Furthermore, Mira's Gehenna Scope magic has also been noted to be quite effective against Chaotic Rune as well.

Satan
By utilizing her Magic King Element and Trinity status, Hijiri is able to transform to the manifested form of the Ira archive, "Satan", which exceeds the normal Magus Mode. Although, in particular, the transformation itself seems to cause her visible pain. Neverthess, In this form, she becomes extremely powerful, being able to hold her own against entire Trinity Seven.

Techniques

 * Black Azazel - Discharges a magical blast toward a target.
 * Vegtam - Also known as "Baldr's Blessing", this spell encompasses as both her offense and defense. She may use this spell discharge a magic blast, as well as form a defensive barrier. Arin's Demon Spear Gae Bolg is the only weapon capable of destroying the barrier.

Grimoires

 * Astil Manuscript (Formerly)
 * Ilias Fragment (Formerly)

Royal Biblia Academy
Arata Kasgua - TBD

Arin Kannazuki - Arin and Hijiri have an unknown connection, as they are both not only physically identical, they use Chaotic Rune to work magic.

Iscariot
Lugh - TBD

Trivia

 * Hijiri's manisfested form of Ira is a reference to the demon Satan. In Christian mythology, Satan is often considered the demon most associated with the sin of wrath. It can be assumed that this applies to other manifested Archives as well.
 * In the first print of chapter 0, Hijiri's hair color was initially brown in the color pages. However, in the volume 1, her hair color was changed to light blue which has been used since then.
 * It is currently unknown why Hijiri and Arin look almost identical to each other.