Vampire Master Dark Crimson

From before the dawn of time, people known as "Crimsons" have been controlled by a deadly foe, the "Clients," who consider themselves gods. Now, at the turn of the twentieth century, the Crimsons still live in fear of the Clients. Powerful individuals protect themselves by making sacrificial offerings of live humans. Dark Hunter, Shion, is half-Crimson, half-Client—in other words, a vampire. Alongside his loyal sidekick, Rain, he wages an endless war against the Clients. When Shion meets Helen—a young girl whose family was butchered by the Clients—he makes a blood oath and takes Helen as one of his followers.