Who is he?

He is Morty (Matsuba in the Japanese version), gym leader of Ecruteak City. He specializes in ghost types and wishes to one day meet Ho-oh in person. He tends to be rather reserved, but is very passionate and loves his friends and pokemon with all his heart. He is close friends with a man named Eusine who is a Suicune enthusiast. According to the manga, he has clairvoyant powers.