Necessary Evil is a Supers meets Post Apocalyptic setting for the Savage Worlds system, pioneered by Pinnacle Entertainment. The basic backstory is that an alien race approached a version of Earth with native superheroes, bearing the banners of friendship. Proving themselves to be nonhostile, they were welcomed to Earth... and then showed their true colors in a surprise attack that slew or captured almost every superhero on Earth. But they hadn't reckoned on the supervillains, who mostly weren't very thrilled about having a bunch of space-men show up and conquer their planet. You play as one of these villains-turned-saviors, leading the resistance against the alien invasion.