World-Saving is a Skill

After two decades battling monsters in another realm, Hyeonseok finally saved that world and was returned to Earth as his reward. Now going by Chanseok, the former deliveryman anticipates a peaceful life enjoying modern comforts. Instead, he finds Earth transformed: mysterious Erosion Points unleash creatures, and those with special powers, called Hunters, rise to fight them. Primarily motivated by financial need, Chanseok reluctantly registers as a Hunter. Having already saved one world, he figures tackling this new threat should be manageable.