Priscilla is the daughter of the princess in the storybook. She was born a royalty among the demons and is well-respected. Her blood can resurrect people. If someone is to be turned into a guard, an agreement with Priscilla needs to be made. This agreement is made with Priscilla offering the person a position as a guard after explaining the things she'll give them in return and the things that the person must sacrifice, If said person agree, the person will be turned into a guard.
Priscilla is the daughter of the princess in the storybook. When she was young, she was raised by both her father, a man from the 'ground', and her mother, the princess of the purgatory, but soon her mother left Priscilla in the care of her father to rule over the heir after hearing a message that her father, the king had died. In her mother's absence, people accused Priscilla of being a child of a demon and attempted to harm her. She ran to the kingdom and towards her mother in hope of finding protection, and her mother, the princess, grew enraged to see her daughter treated badly by other humans. As a form of expressing her rage towards the humans, she created the seven deadly sins to judge them, swearing that no other human would enter her kingdom unless they deserved to.
Priscilla was the person who offered Sue to become a guard. When Sue was locked in a room for a problem he caused, Priscilla appeared to him and offered him to see something interesting. Sue grew interested and she gave Sue an option to become a guard while mentioning that she'll give him anything he wanted if he agrees. Sue agreed to become a guard if Priscilla grants him 'freedom'. Priscilla is surprised over how simple and easy Sue's wish is and Priscilla told him that he'll lose his memories as a sacrifice, asking him to reconsider his choices again. Sue mentioned that he could care less about his memories and agreed to become a guard as long as he can get his freedom.
In Hide and Seek: Story of Dorothy, Priscilla greeted Sue at the last scene of the true ending: Priscilla, which took place several years after Dorothy's death. The scene took place when Gwyn went to the 'waste residence' to find his medicine. Priscilla expressed her disgust for Sue's 'evil hobby' in this scene.
In Hide and Seek: Stranger, the scene from the previous true ending continued. Her short conversation with Sue turned bad, when she found that Sue stole an important item from her. She became annoyed, and threw the boy to another dimension known as the forest. In this dimension, Sue found out that he couldn't use his powers, but managed to go out. Later on, it is revealed that the 'Sue' that was thrown by Priscilla into the forest is not Sue, but Ai, who took a form of Sue.
After meeting them, Priscilla was suggested by Sue to revive Gwyn, who was already dead from an encounter with his father, Theophillus Damien, when he explored the mansion. Priscilla revived Gwyn with a drop of her blood and brought him back to his theological school for a rest. After Gwyn woke up, Priscilla gave him an option to become a guard. In exchange, she'll grant him freedom. Gwyn agreed, and the story ended.
Priscilla is shown to be a reluctant woman who often got tired by her 'guards' sadistic tendencies. Often times, she recruits people reluctantly, more interested in getting the process done rather than 'playing around' like Sue and Ai did. Among the three demons, she showed the least, if not, no tendency to take joy on her victim's suffering, treating them much like a job or a responsibility rather than a plaything. She has shown concerns towards a few people and even grew surprised when people took her 'offer' without any consideration, asking them to reconsider things carefully, and even giving the a choice to deny the option. She often change her age appearance to her liking.