There are four evil dinosaur powers that exist, created by dark forces in order to bring plague, war, famine and death to the world. These forces pass around, possessing people who don't know what's going on, turning them into servants and hosts of darkness.
These four Kyoryugers are stronger, faster, and more powerful than their counterparts. They each have unique abilities, ranging from turning friend against friend, to draining the life out of whatever they touch. It is their job to spread dysfunction and fear, and use the power of the ancient dinosaurs to crush all resistance they can.
If the host overcomes them, the battery moves on and finds a new host to turn.