The year is 2023 5:43 A.M. a child is being born. But, something is wrong. His skin is pale green his eyes and finger nails are pitch black. The parents think it is just a medical conditions so they raise it as a normal child. They think it will get beter with age, but the opposite happens. It's skin darkens its eyes get larger, and its finger nails turn to claws. The government sends the beast to a secret facility. They find it it is self-reproducing. It has children and they escape the facility and go into hiding.....
1300 years later the new morphed species has taken complete control of the world. Only 15,000 or so humans remain, but have evolved slightly to fit the situation. They have sharper teeth, more intelligent brains, and more muscle mass. Technology hasn't advanced because with the gain of brute force the morphed race is less intelligent so the same modern tools and technology exists. Your role in this RPG is to either escape Earth and get to a more inhabitable planet, or destroy the strange race and regain dominence.