Killing Killer

10 years ago, Lee Si-woo, the main character who lost his parents to a murderer, finally met Jack, the murderer who killed his parents, and cut his throat…
But the decapitated head never died and talks to him, “I’m not the one who killed your parents.
” Knowing that the real culprit is a ‘contractor’ belonging to a group of killers with superpowers, Si-woo decides to hunt the registrants with Jack’s help