Synopsis: Killing Killer

Siwoo Lee, the main character, lost his parents to a murderer ten years ago, and eventually meets Jack, who is believed to be the culprit. Seeking revenge, Siwoo beheads Jack. But before he dies, Jack admits that he was not responsible. To find the real culprits, Siwoo learns that a group of assassins with abilities employs a "contractor." Together with Jack, Siwoo embarks on a quest to find the perpetrators. This story is originally a webtoon series.