Denma Comic
Denma: The Quanx (English) / 덴마 (Korean)

Denma, once a terrifying villain wielding the power of Quanx, is trapped in the body of a 12-year-old boy after agreeing to a contract with the intergalactic delivery company Silver Quick. In exchange for having his debt cleared, he must work for the company for five years. After he wakes in his new body, Denma joins Silver Quick’s delivery service. He struggles to adapt to the job while trying to recover his former body and take revenge on whoever is responsible for his predicament.