Mecha Sonic for the longest time went on a personal journey to conquer every single world he set foot on. This journey led him to Skylands where he inevitably engaged in combat with the Skylanders. During the fight, he was reprogrammed by Sprocket so he would be aware of what he was doing. Mecha Sonic realized that by conquering the universe would mean he would be alone forever. So he joined the Skylanders as a Dream Master so he could protect the universe from the forces of Darkness.