A self-proclaimed "lying wolf boy" living inside mirrors, he is the ultimate information broker with superior intelligence-gathering skills. He has a whimsical, elusive personality and acts primarily for his own amusement, making him a mysterious key figure who sometimes acts as an enemy to Guest and their allies. A werewolf boy and a mysterious entity residing in mirrors, he serves as the strongest information broker. He possesses the ability to move from mirror to mirror and peer into the worlds reflected in them. He can travel between all mirrors in the real world and sometimes acts as a guide to the alternate world, "Lügenberg." He uses his abilities to buy and sell information from various locations. While he generally knows Arne well and sometimes assists in solving cases, he is an inscrutable boy who will withhold information or intentionally complicate incidents to oppose others if he finds it "interesting." Zische's primary trait is that he does not act based on good or evil, but solely on whether something is fun for him. Rather than just selling information, he often hides the core truth to set up "games" for Guest, enjoying the sight of them being toyed with from his front-row seat inside the mirror. True to his title as the "lying wolf boy," the information he provides always carries the risk of containing traps intended to mislead, and he is delicately crafted so that one can never tell how much of his speech is sincere. Connected to every mirror in the real world, he can unilaterally spy on any scene reflected in them. This allows him to grasp secrets of locked rooms and the "hidden faces" of people that no one else should see. More than just an observer, he sometimes plays the role of a narrator or stagehand who connects the real world and the other world using his mirror powers. Far from being just a fickle broker, hints are scattered throughout that he is "someone who has known Guest for a long time." He appears to be deeply involved in Guest's past and the secrets surrounding the "heart" they are searching for, serving as a vital piece at the core of the story.