The Zone was primarily used as the third base of Doctor Robotnik, set up after the fall of his empire so he could investigate the Flickies' origins and use them as organic batteries for his new army of Badniks.After coming into contact with the Drakon Empire, Robotnik would continue to use the Rusty Ruin Zone as a base, launching armies of Badniks from there until he became a God with the power of the Chaos Emeralds.