Do you believe it? There are such a group of people hiding in every corner of the world. They are like ghostly vampires, hiding day and night, elusive, bloodthirsty and aggressive, and will not stop fighting. The biggest difference between this group of people and the hidden vampires is that they may have to continue to live in chaos in this world, living under another dignified identity in the sunshine. And once night falls, most of them will put on night clothes, bring heavy equipment, and wander around various parasitic corners to absorb their necessary nutrients. If vampires are still united to fight with werewolves, humans and other aliens for profit, then the only enemies of this group of people are their own kind, or even companions. This group of people has a unified name, which is dark and obscure, and they are called killers.