Chi

Kai (カイ) (χι) is a member of Shadow Garden, being one of the Numbers. She primarily works as a direct subordinate of Epsilon.

Appearance
Kai is an elf with short blonde hair and blue eyes, with an eyepatch over her right eye, with an athletic build and a modest chest. She sometimes decides to dress more in men's clothes, since according to her, it helps her to collect information in different details, other than what she likes as woman.

Personality
Little is known of Kai's past or personality, other than she was abandoned like the others in Shadow Garden when stricken with Demon Possession and became loyal to their cause of destroying the Cult of Diablos.

Background
Like the other girls descended from the Heroes who now join Shadow Garden, Kai was discarded and abandoned by society after contracting demonic possession. She was found and rescued by members of Shadow Garden alone in a dark back alley, malnourished with the curse spreading over her body, sleeping in trash. Shadow Garden cured her, elaborating the truth, earning her loyalty and subsequently recruited her into the organization. Being among the earliest recruited when Shadow Garden began expansion, she was renamed to Kai. A few years later, she established a strong and direct relationship with Epsilon, one of the seven original shadows, and worked together with Omega to become Epsilon's direct subordinates. Kai rose through the ranks to become one of Shadow Garden's double-digit numbers, a testament to her prowess and ability.

Holy Ground Infiltration
When Shadow made himself known to battle the memory of Aurora, Kai was among the Shadow Garden contingent that followed Alpha, Delta, and Epsilon into the Sanctuary. Inside, Kai and Omega followed Epsilon with a unit of Numbers to collect intelligence from the memory world within the Sanctuary, confirming some theories on the Cult's origins, learning new details, and understanding their motives much better. Kai followed Alpha's order to leave the Sanctuary, leaving Acting Archbishop Nelson to battle Shadow. Following the Sanctuary's destruction, Kai and Omega escorted Alpha and Epsilon out of Lindwurm with the intelligence they collected.

Powers & Abilities
Kai has been trained to use and control her magic, as well as fighting practices, based on lessons passed down from Shadow. Kai quickly rose through the ranks to become a double-digit Numbers in the 20s, thus a Named Number. She was eventually assigned to be the direct subordinate of Epsilon of the Seven Shadows.

Physical Abilities
Kai, like many before and after her joining, trained daily to improve upon her physical prowess. Such is necessary to be ready for a fight or to retreat to safety. This includes self-defense, martial arts, and strength training.

Swordsmanship
Kai is proficient with a blade, as are all of Shadow Garden, but Kai is likely a master to some degree having earned a Named Number rank, as well as serving as direct subordinate to Epsilon.

Magic
Kai is proficient in magic, having maintained her Slime Bodysuit during the magic distortion effects of the Holy Sanctuary Infiltration. Such is a requirement given Epsilon's renown within Shadow Garden for her refined magical control.

Quick Flash
A speed augmentation ability, derived from the early practice of speed magic Shadow taught the original Seven Shadows.

Standard Equipment

 * Slime Bodysuit: A standard issue in Shadow Garden, with Kai's having notable decoration to express higher rank and authority within the command structure compared to the rank-and-file.
 * The Rolapoid: An instant camera for missions of espionage, a reverse-engineered technology from Shadow Wisdom by Eta.

Shadow
Kai is steadfastly loyal to Shadow, aware of his secret identity as Cid Kagenō. It was his methodology that developed a cure for Demon Possession and provided her a new purpose against the Cult for their conspiracy against her nearly taking her life.

Alpha
Kai as such, respects and obeys Alpha's orders as the one who directs everything by being the second in command, when her Lord Shadow is not present, in addition to having some security by having her as one of those who helped her, along with Epsilon.

Epsilon
Kai works as a direct subordinate of Epsilon, and is aware about her fake slime body, but pretends not to notice it as she cares about her.

Omega
As both are direct subordinates of Epsilon, both have developed an efficient process under their commander. Both have also shown a slight display of friendship when in their civilian dress.

Trivia

 * According to the director's tweet about Kai's illustration, the symbol to represent her name is χ, which is Number 22 from the Greek letter. In fact, the very first sentence from the Wikipedia page for the letter is already explains how to pronounced it.