Who is King Macgready?

Explorer his origin story, written by Jason Hall:

Over the centuries civilizations have risen and fallen, while vampires hid in the shadows. Now, it may be too late to stop them from driving the human race to extinction. One forgotten hero, Kurt Macgready, a half human/ half vampire hybrid, lives hidden in the forest village of Everlaste and may hold the secret to ending the curse of the dreaded vampire nobles. Travel to the futures past where earth is without technology and a place where terrible magic begins to emerge again.