Seoul Station's Necromancer

After years of fighting for survival on planet Alphen, Kang Woojin had become a fearsome necromancer and ruler of his own territory. But now that he’s finally found a way back to Earth, he’s nothing more than a low-level player clearing dungeons for cash. Soon enough, though, Woojin’s undeniable skills have major guilds vying for his attention. And just in time, because with Woojin’s old enemy threatening invasion, those skills might be the only thing standing between humanity and destruction!

(Source: Tapas)