It happened about a year back. For most of his professional career, a scientist by the name of Alexander Willow worked on trying to find a way to extend the life spans of his beloved pokemon. What he accidentally discovered instead was a way to bring dead pokemon back to life. But before the effects of his life giving serum could've been fully tested, it was stolen from his lab in the Sinnoh region by a crime organization who wished to sell it on the black market. Soon, people were claiming that their pokemon were rising from their graves everywhere. While some remained weary of the events unfolding others thought it a miracle until the pokemon who returned from the dead suddenly started attacking their trainers and began turning feral as they rampaged all over the region.
Soon the virus began spreading to other parts of the world like a wildfire, infecting other pokemon and humans alike as cities and towns began to fall while people ran screaming for their lives when their loved ones suddenly began rising, hungry for blood. Whole regions began disappearing off the face of the planet, becoming barren wastelands of nothing but dust and corpses but the Kanto and Johto regions however, have managed to survive all the chaos and have barricaded themselves from the virus. Watch towers were immediately built up in each town and city and is well guarded to make sure the virus stays out. But with survivors flocking to both regions from all over the world, it'll only be a matter of time before the dead will begin to invade as well. The world has turned into a jungle and merely it will take more than merely just battling with pokemon to survive anymore...
It's A Jungle Out There
Zombie Pokemon