Occult Slayer

Monstrous beings known as "Terrors" erupted into the cities, hunting humans by night and turning their victims into monsters just like themselves. For their own safety, the Federation and the elite rich built the Floating City, from where they can govern the planet remotely, while ordinary citizens remain on the surface to produce goods and services. To hold the line, the Federation established an early warning system and assembled a team of protectors called the Night Watchers. Among the Night Watchers, Dexter Li, the host of the Ghost Slayer System, is a unique existence. Other Night Watchers grow stronger through their special abilities, but Dexter Li gains abilities and energy from killing Terrors! One hit, one kill! When strength comes this easily, can you really blame him for being unstoppable?

Official Translations:
English (Webcomics, Webnovel), Japanese