Sullivan seems to act rather childish at times. He is quick to cry when his daughter Kurotsuno tells him to leave and when Glasses later drags him away. He is furthermore very affectionate towards his daughter, and easily cries when she is cruel to him. It seems he also can be violent and often gets into confrontations with Gyakuten, Hanten has stated that Sullivan, "ain't got the best temper," a trait he shares with his daughter. Despite being a demon, Sullivan has various health issues.