He/She is an 15 years old,has got a navy blue hair, favorite food is "sukiyaki".Finally, He/She says: "I swear to god I'll surpass you!!, just you watch!" "I'll become an exorcist and kick Satan's ass!"
He/She is an 18-year-old and the Student Council President of Honnouji Academy. She/He rules the school with an iron fist and assesses the students' abilities, holding the position/authority to assign the powerful Ultima Uniforms. She/he does not wear a Goku Uniform, stating that her sword, "Bakuzan" is more than enough power and protection, though she/he eventually starts wearing a Kamui, "Junketsu".
He/She is usually deliberately drawn in a simpler style than other characters, with a very rounded head and only a simple mouth and eyes. When drawn in a more 'action-oriented' style with more detail, he/she is revealed to have sharp features, dangerous looking eyes, and chiseled musculature.
He/She is the namesake "monster" of the story and the mystery of his past is the focus of the plot. He/she has been called a monster, the next Adolf Hitler and even the devil ....self. He/She was shot in the head at a young age but saved from death by Dr. Tenma. Because of this, he/she is very grateful to Dr. Tenma.