He acts as the director of the academy, and since you're a new student, he will teach you many things about your school. He can be strict, but he can also be kind. During the story he also introduces himself as Clive, a school student, during your adventures fighting Team Star. Clavel is middle to older-aged. An Intellectual man with a vibrant soul, Clavell cares deeply for his students’ wellbeing and futures and, despite his seemingly stoic demeanor, he is always there to listen to and guide the next generation to greatness. As Clive, he tries to come off as a student. Although it is played for laughs for the audience, there are those in the game who fall for his disguise. 

Voice type: 
Clavell - Experienced and intellectual, with a natural zeal and curiosity about life. Caring and considerate about his students.
Clive - Any interpretation is valid for this. It could be funny to change up the voice entirely or sound generally the same like this.