Spiker, Atro

Atro was the master of Adlet, who taught him to laugh at whatever is going to happen, since laughing is the best way to become strong. Atro is known for his insane, torturing lessons which led to every student, except for Adlet, running away from him. Atro taught everything he knew to Adlet in order to allow him to be the world's strongest and to also beat kyouma. Atro is also knowledgeable in science and weapon-making.