Spirit king's ascension

A world where otherworldly monsters invaded, when humanity seemed to be coming to an end then a few of people awaken with special powers. they're called hunters. Arun was a non awaken who was worked as a labor in dungeons. although he was risked his life everyday, he couldn't afford treatment for his younger sister who was suffering from hypermana disorder. one day he went to the monsters field and found a cave where he made a contract with the demon king and awaken a special class. he wanted to become enough strong so he could protect his younger sister. and then he was started to hunting the monsters with the demon king.....