BC, short for Buzam A. Calessa, is the sub-commander in charge of the Nirvana's crew welfare. She has a stern demeanor and takes her job seriously. As an experienced tactician, she gives orders with authority and precision. It appears that BC is highly dedicated to her work, often spending time near the bridge to monitor data and evaluate the team's performance.
During the initial episodes, she is seen secretly taking a small, data disc from the bridges database, until Magno interrupts. However, her suspicious actions do not seem relevant until the Second Stage, where it is revealed that she is actually the Commander of the Taraak Intelligence, whose real name is Tenmei Uragasumi, a male spy for Taraak. However, in the end, Magno Vivian forgives "her" and retains "her" position as sub-commander, on the provision that "she "stays as BC.