Humanity has finally done it and destroyed the world.
After the spread of the killer virus that no one had a cure for, countries started to fight as greed has pushed them to expand their territories. And in the process, they provoked mother nature to take a stand.
The plague evolved into something that twisted and deformed humans; they were neither dead nor alive. Just walking empty husks that fed on flesh and had one purpose, killing.
The supernatural were exposed to the rest of the world; as they weren't spared and got affected, too. The result of this knowledge was chaos.
Instead of creating one unity, the rest of the living were fighting among themselves and the undead.
The entire world turned into a big arena and it was (survival of the fittest).