Sebastian is a human whom is quick to anger, yet manipulative and stubborn. He has his moments of being calm, but he is a textbook narcissist. His father died when he was 11, and his mother blamed him for his death. He was physically and emotionally abused, even as he dated a person named Yuko. Sebastian physically and mentally abused Yuko as well as going as far as ripping their eye out and making them eat it for fun.