Arbatel

Arbatel is a mysterious Grimoire created with magic by unknown backgrounds. With the information she has absorbed from the real world, she has become a rom-com otaku with a obsessive desire to create the perfect rom-com world. The Grimoire Arbatel is the main antagonist of Volume 18 as she absorbs the consciousness of Kimihito, his household girls, and numerous other people in order to take them into her world and brainwash them into believing that they are students of Grimoire High School.

To blend in with the crowd of people in the Grimoire, Arbatel changed her form and took on the identity of Honma Shiori, a member of the school's library committee.

Appearance
In her true form within the world of Grimoire High School, Arbatel appears as a young woman with fair skin, dark hair and a mostly human appearance. She wears glasses and her eyes have triangular pupils resembling the symbol of the cover of the magic tome. Her attire consists of a witch hat, off-the shoulder sleeves, a robe that starts at her mid-chest (both it and the sleeves end in layers reminiscent of an open book with several pages behind the hard cover), and long black trousers.

In her disguise as Honma Shiori, Arbatel has the appearance of a young human woman with black hair. She wears glasses as in her true form and is dressed in the usual school uniform, consisting of a seifuku with a plaid skirt.

In the normal world, Arbatel doesn't have a humanoid form and is a book on which there is a symbol of a circle with a triangle in the middle. The book was sealed with a black ribbon to prevent anyone from opening it.

Personality
Arbatel's personality has been greatly shaped by her long stint at the Kayado public Library, where she was housed in a section of school-themed rom-com manga. By absorbing information from the manga, Arbatel has become a rom-com otaku with an obsessive passion for creating the perfect rom-com school world. Typical of rom-com Otakus, however, Arbatel's desire was limited to secretly observing the romantic interactions between the couples at school, since it is love and the lover's relationships themselves what rom-com otaku love about rom-coms. Arbatel doesn't want to enter the world of a love comedy herself.

Arbatel's obsession went so far that she absorbed the consciousness of hundreds of humans and Liminals, brainwashing them into believing they were really "students" at Grimoire High School. This shows a partly ruthless side, as Arbatel held people captive against their will, solely due to their selfish and petty desire to secretly watch the rom-com events between the students. Ultimately, however, Arbatel does care about the welfare of others, as it is revealed in Chapter 76 that whenever Arbatel has absorbed a person's consciousness, she would use her magic to summon an ambulance to take the people's unconscious bodies to a hospital, so that nothing happens to them.

Arbatel is also very proud of the Grimoire High School rom-com world she created. In Chapter 80, she called the world "perfect" and "beautiful".

Furthermore, Arbatel also proved to be clever as she set a trap for the MON-team to absorb their consciousnesses into the rom-com world. The MON-girls had to play the role of the Five Mysteries of Grimoire High, who roamed the school at night so that they would not pose a threat to Arbatel. However, Arbatel showed a rushed side in this regard, as the MON-girls were not brainwashed and were still free to roam around the school. Arbatel also didn't seem to care if a student would break out of their brainwashing by removing their uniform, as she was completely unaware that Kimihito's household girls from Chapter 77 were no longer affected. This shows that Arbatel didn't consider long-term consequences or risks for her plans.

While Arbatel had a fondness for most rom-com genres, she deeply hated harem rom-coms. Because of this, she developed a strong dislike for Kimihito, since he lives together with seven Liminal girls, but has not been in a committed relationship with any of them. She considers him a "harem rom-com protagonist". For this reason, Arbatel purposely didn't brainwash Kimihito when she absorbed his consciousness, hoping the Grimoire world could change his "filthy harem obsessed heart". This shows that Arbatel has a very biased side, as she didn't actually know Kimihito and her dislike for him was only based on her misconception, causing her to see him as a person he wasn't.

However, after Arbatel (more or less) participated in a rom-com event in Chapter 80 herself, she fell into a kind of depression because she can't be someone who falls in love at first sight. As a die-hard rom-com otaku, Arbatel considered it something of a sacrilege that she even thought of partaking a rom-com event instead of just watching. As a result, Arbatel released the consciousnesses of all the people she absorbed, believing that she no longer has the right to look over this "perfect world".

Skills & Traits
As a Grimoire, Arbatel possesses a variety of abilities, all related to magic. This makes it difficult to give an exact enumeration.
 * Information absorption: As Ms Smith explains in Chapter 74, a Grimoire can absorb information from its surroundings and then use magic to affect its environment. The exact mechanism behind this ability is unknown.
 * Shapeshifting: A Grimoire can change its shape in both its book form and true form. In the real world, in Chapter 76, Arbatel was able to change the appearance of her book form to look like a normal rom-com manga to set a trap for the MON-team. Within the Grimoire world, Arbatel was able to alter her appearance to resemble the school's library committee member Honma Shiori.
 * Consciousness absorption: A Grimoire can absorb the consciousness of any person who attempts to read it. The person's body faints while the consciousness is brought into the magical world that the Grimoire created within it. The only known way for an absorbed person to exit the Grimoire's World is for the Grimoire to release the person's absorbed consciousness.
 * Ambulance summon: As Zombina explains in Chapter 76, after absorbing a person's consciousness, Arbatel would always summon an ambulance, which would take the unconscious bodies of her victims to a hospital for their safety.
 * Magical World: A Grimoire can use the information it has absorbed from the real world to create a kind of magical "fake world" that appears to be separate from the real world on a plane of its own. As the creator of this world, Arbatel has full control over it, although world warping can occur when Arbatel is unfocused, as seen in Chapter 80.
 * Brainwashing: As a Grimoire, Arbatel can brainwash the people whose consciousness she has absorbing into believing they are "students" at Grimoire High School. However, this brainwashing only works as long as the absorbed people are wearing the enchanted school uniforms, and if one of them takes off the uniform, he or she will be freed from the brainwashing. However, as revealed by the example of Kimihito, Arbatel can also consciously choose to absorb someone's consciousness without brainwashing them.
 * As seen in the example of Kimihito's household girls, Arbatel does not seem to be aware of whether a "student" is wearing the school uniform or is still being brainwashed.
 * A Grimoire can also directly affect the people it absorbs, such as when Arbatel used her magic to change Tionishia's size to ten meters.

History
Much about Arbatel's past and origins is largely unknown, but according to Ms Smith, a Grimoire was originally just a normal book that was altered by the magic that imbued it and is now a kind of Liminal. Given this, it is possible that Arbatel was originally a book owned or made by a wizard, although this is unconfirmed.

The Grimoire, through unknown circumstances, ended up in the possession of the Kayado Public Library in Japan, where it was housed in a section containing only school-themed romantic comedy manga. By absorbing the information from the manga, Arbatel developed a great fondness for rom-coms, although at the same time she also harbored a strong dislike for harem rom-coms. However, just reading the manga made Arbatel not a rom-com fan, but a rom-com Otaku, which meant that she only wanted to be around love couples to see their little moment of love between them. Arbatel had no desire to experience a romantic comedy herself.

Arbatel eventually came up with the plan to create the perfect school-themed rom-com world, the world of Grimoire High School. Somehow Arbatel found out about Kimihito, and due to the fact that he was living with seven Liminal girls but couldn't get into a committed relationship with any of them, Arbatel quickly developed a strong dislike for him. She considers him a "harem rom-com protagonist" and on occasion planned to absorb his consciousness to bring him into her world to change his "filthy harem obsessed heart".

Plot
After Arbatel created the world of Grimoire High school, just prior to the events of Chapter 74, Arbatel began absorbing the consciousnesses of humans and Liminals reading the book. When a person read the Grimoire, their body fainted while their consciousness was absorbed into the magical world of the school. The enchanted Seifukus brainwashed the "students" into believing that they were actually students at the school. However, since Arbatel also cared for the well-being of the people, the Grimoire always used her magic to summon an ambulance, which took the unconscious people to a hospital for their own safety.

Of course, the series of people fainting en mass didn't go unnoticed for long and was also reported on the Japanese morning news. After secret investigations lead to Arbatel being responsible, Ms Smith hires the girls from the MON to remove the Grimoire from the Kayado Public Library and take it into custody. However, this plan backfires when Arbatel secretly sets a trap for the MON-team by disguising itself to look like a normal manga. And when Zombina finally opens the book in an inattentive moment, Arbatel absorbed the consciousnesses of the four MON girls as well.

Zoological Classification
A Grimoire was originally just a normal book, but due to the magic that has been imbued into it, it is now some kind of living being or Liminal, although it is difficult to define whether the book is truly "alive". A Grimoire absorbs information from its environment through unknown mechanisms, and then used that information to affect its environment through magic. Grimoires possess a variety of abilities, such as absorbing the consciousness of people who read them and then trapping them in a fake magical world created by the Grimoire itself. This makes a Grimoire potentially dangerous, but also one of the most mysterious Liminals.

Trivia

 * Arbatel is the first Liminal in the series that can be viewed as both a living being and an object.
 * In real life, Arbatel: On the Magic of the Ancients was a Latin grimoire of Renaissance ceremonial magic published in Switzerland in 1575.
 * While Chapter 80 confirmed that Arbatel was not arrested, her fate or whereabouts are currently unknown.