The Chaos Resonator is an unseen device created by Doctor Robotnik that was brought into play during the Chaos saga. The machine was designed to emit an artificial Chaos signature and act as a beacon to attract the Chaos Emeralds after they had been scattered across the world. The Resonator succeeded in drawing the emeralds and the Chaos creature itself to Robotnik's Retreat, where the monster confronted Sonic and the other heroes in a final battle to determine the fate of Mobius. The Resonator was most likely destroyed when Perfect Chaos tore apart the retreat.