The Genius Assassin of the Apocalypse

Jung Hyun-soo, the industry's greatest genius assassin. Just as he and his younger sibling were on the verge of death after being discarded like a used tool, the world ended. A world now overrun by systems and monsters. Having become a Player, Hyun-soo intends to take care of his family in accordance with his deceased sibling's last wishes. However, it is not an easy task.