They created genetically 'perfect' humans. They had all the positive traits of a person and not a single negative one. They were smart, kind, selfless, athletic, street smart, you name it. They were meant to be the perfect subject that followed orders and helped out 'imperfect' humans.
But they didnt. Instead, they took over the world and massacred any human not deemed perfect. Now, those who aren't 'perfect' have to run for their lives.... Or be killed without a second thought.