Sarah

"Fight and resist lots, okay? After all, that's how you get stronger creations..."

- - Sarah to Keith; Novel Volume 4, Chapter 2

Sarah is a dark magic user with high magical aptitude.

She does not have a real name, as the children who were experimented on by the Dieke family were classified through numbers. Sarah is a pseudonym.

Appearance
She is a girl with long black hair. She has the innocent and adorable smile of a child. Despite looking friendly, she has a very dangerous aura around her.

Personality
Sarah is a girl who responds very passionately and enthusiastically to stories involving revenge and tragedies. She is manipulator, who can control and convince people to do her bidding. She is the puppet master of several incidents involving Dark Magic, such as Keith's kidnapping the the disturbance of a forest. Despite being around the same age as Thomas and Keith, she acts very childlike. She has a very inconsequential tone in her vice, even when talking about dark topics.

Background
When she was a slave, she along with other children were sold to the Dieke family to use as test subjects for studying Dark Magic. Orphans and slaves brought to the Dieke family would be given dark magic, as part of a contingency plan, or Plan B, just in case the plan involving Sirius and Raphael failed.

The information gathered from the children are shared by the Dieke Family to those who desire to gain Dark Magic. Due to the nature of the experiments conducted to the children, many of them either died or lost their minds. Among the children is a young girl who was known for her high dark magic aptitude, who is revealed to be Sarah.

The Dieke Family attempted to dispose of all the bodies of the children involved in the experiments, but the crooks commissioned to do so did not finish their work carefully, leading to some of the children surviving.

Whether or not Sarah is committing crimes as retribution against Katarina for bringing down the Dieke family, or if she had simply lost her mind and commits crime for her own amusement, is still unknown. She is currently going around Sorcier conducting more experiments involving familiars of darkness, by extracting the life force of civilians and nature.

Sarah is currently participating in a lot of illegal and criminal activity, by providing aid to many aristocrats and nobles with her powerful dark magic.

Master
Sarah works for a mysterious nobleman who had saved her after her escape from the Dieke Household. She is very loyal to him, being very willing to experiment and kill in order to help him achieve his goals.

Thomas Coleman
Sarah approached Thomas when he was in a state of distress out after he had lost all his money and reputation. She comforted and listened to him enthusiastically as he fantasized about Keith's downfall. She generously provided him food, drinks and a mansion to stay in, by controlling servants with Dark Magic. Thomas ended up falling in love with Sarah, as she was someone who didn't mock him for his distorted thoughts and desires.

Despite Thomas thinking that they were allies, in reality Sarah was just amplifying his negative emotions so she can absorb it along with his life force, in order to power her dark magic.

Keith Claes
Sarah desired to use Keith as a guinea pig for her experiments involving Dark Arts (it is implied that he was using him to create more familiars of darkness), as she was in need of a person with a strong body and heart. She is aware of Keith's tragic past and shared in Thomas' desire to see him fall, though her only goal is to use him until his heart breaks down.

Katarina Claes
Ever since Keith's kidnapping, Katarina and Sarah unconsciously (or maybe even intentionally) run into each other in several occasions, where the strength of their dark magic is put to the test. Katarina's familiar Pochi manifested from an experiment conducted by Sarah. She is intent on getting a hold of Katarina, in order to study the mystery of her Dark Covenant and Familiar of Darkness.

Raphael Wolt
Sarah was one of the children who were planned to use as a backup plan in the event that experiment involving Sirius and Raphael failed. Since Marquess Dieke assumed that the experiment worked, Sarah and the other children were disposed of.

Dark Magic
Sarah, according to Lana, knew too much about Dark Magic that even higher-ups in the Ministry are not aware of, such as the existence of familiars and how to craft them, as well as absorbing the energy and essence of an individual in order to refill and bolster one's dark magic.

Trivia

 * She has created several dark familiars with two of the known ones being the form of a snake (her attempt using Keith's life force) and a dragon (created from the life force of a civilian).