Destiny calls
Vampires are contractors like the Dragonites and are in fact far stronger, second only to the extinct spell casters. However, the celestial contract robbed them of their rightful place on the hierarchy.
They possess superhuman strength, speed, and enhanced senses, but only if they feed. The mortal piece of the celestial contract renders contractors incapable of harming humans, like shackles that bind them beneath mortal feet even if it means their demise. Over time, they grew weaker without human blood. For some reason, the sight of it or the smallest whiffs made them sick.
Without the will to live, the dark prince took those he had turned and hid in the underground city of Babylon. They lived in solitude, hidden from the world, and left to feed on rats and varmints. They starved and slowly, their numbers dropped.