Hassel is a descendant of a long line of Dragon-type Trainers in an unnamed faraway region. He ran away from home as a youth to pursue a dream of "making music", before becoming a member of the Elite Four in the Paldea Region as well as an art instructor at the academy. Hassel is shown to be friendly, but very emotional, as he bursts into tears of joy when defeated by the player. He is an old friend of Gym Leader Brassius of Artazon. At one point, one of Hassel's relatives tries to convince him to come home, but his students' support prompts him to remain at the academy.