Earth became unstable. Over populated, numbers reached such a high point that the planet simply couldn't sustain the life it carried anymore. Governments were struggling, local agencies were drowning, resources were becoming depleted.
The decision was made to ' thin the population.' Some dark corner of a corrupt government agency decided to unleash a virus. One that would only take a few here and there. They thought it was the only way to stop the breakdown of societies, and prevent the loss of entire populations. So, they created a disease that would simply sweep through, selecting only a few here and there, based on certain proteins in human DNA. Since the proteins were not carried by everyone, there was no way their plan could fail.
But it did.
The virus was introduced into the water system as a way to infect many all at once. However, the plan backfired, reacting in a way that no one had anticipated. While it did kill some the population, to others it did something much worse. Many of those that died began to come back. Some never died at all but were inexplicably altered in ways no one could explain.
Those that died and returned were different. Wrong. They looked every bit as humanoid as before, but somehow, they were more. Mesmerizingly beautiful creatures that seemed to glide above the ground drifting in and out of shadows like wisps of a dream. They rejected the light, for where it had once been a welcome warmth, now it burned their pale, cold flesh. They became vampires, feeding on the blood of the living, using stealth and manipulation to capture their prey. Sometimes the victims died, other times their contamination was spread to their victims, and they too were turned to join the undead.
Others affected by the disease didn't die at all. They changed. Their humanity seemed to fall away, turning them into ravenous beasts, with teeth and fur. They became monsters almost, human and alive, all of which could fall away in the blink of an eye, in a frenzied rage that was satiated only after a kill. They became known as the werebeasts. Humans that can take on the figure of a half beast and half man.
Many of these new creations quickly banded together, hiding away from normal humans. They sought out shelter, in abandoned areas in towns, often joining up based on their similarities and beast-like nature. They avoided human interaction as much as they were able to.
The vampires hated the beasts, perhaps, out of jealousy that they could still walk in the light. Possibly because they were considered ' impure?' No longer human, the vampires were arrogant, and many felt the beasts should be their slaves, even a quick meal in a pinch.
As a result, the two races became enemies, warring brutally with one another when their paths crossed.
The government tried to cover up their mistake, cutting off news leaks about those that changed. They held such a tight reign over this information that most of the population was none the wiser about what had occurred in their midst With the use of their lab built super soldiers, or Reapers, they began to exterminate the infected and pollute any possible information leaks with so much fancy that they seemed imagined. They did such a good job of it that the existence of these two races quickly fell into nothing more than myth and legend. Vampires and werebeasts alike were forced so deeply into hiding, sometimes even in plain sight, that the humanoid world was never disrupted by their presence.
It wouldn't be until many years later, when their world was at an end, that humanoids would come to find out just how terribly mislead they had been by their government. Many things would come to an end that day, leading to a new and often frightening beginning on a new planet.