Satou no Oba

As the relative who assumed full guardianship of Satou following the tragic death of her parents, this individual played a pivotal role in shaping her unstable psyche. Through years of caretaking, she became the primary influence responsible for driving Satou toward her current state of deranged psychopathy. Her actions and upbringing are the fundamental catalysts behind the character's descent into madness and her subsequent development as a dangerous antagonist.