An advanced race who left Earth millennia ago.
The group was responsible for guiding and possibly even seeding the Human race on Earth. They left as the "Kindermen" were starting to rise. Before they left though, they left behind the Innocent Gun for an innocent Kinderman in the future to use against the greatest trial men would ever face, though the gun could only be fired once. Though the human might make the wrong choice, it would be humans who would make the choice when to use the weapon.