The older, taller, and apparently stronger big brother of Daniel and Sarah. Aged eighteen at the beginning of the story, and is five years Sarah's senior. At the age of 12 and a half he had an early growth spurt and gained a strange type of Soul Perception ability in addition to his soul becoming stronger. Not long after, at thirteen, his parents were killed while he was still at the academy, and Sid asssumed guardianship over him and Daniel, his Weapon.
Headstrong, stubborn, and uses the weaknesses within people's hearts to make himself feel better. He has a strong self-loathing and inferiority complex; to compensate for that he retains a near-constant sadistic mindset, and disreguard for life in general. His only loyalty is to Medusa, and it is nearly as powerful as Soul's loyalty to his friends.