Karl's subject is a thin male with a sickly appearance. He is pale and weak with a glazed look in his eyes. He is barely able to function independently and is constantly monitored by Karl and his assistants. He is extremely loyal to Karl and trusts him with all of his heart despite his condition. Karl has done everything he could to keep him alive but has yet to find a cure.

Karl is the main scientist at "The Müller Institute for Advanced Science".