Metal Sonic v3.1 was built by Eggman to engage Shadow in combat and defeat him, but they knocked each

Metal Sonic v3.1

other unconscious. Metal Sonic later captured Sonic and brought him to Eggman, Eggman used a machine to control Sonic, it was also programmed to keep Snivley from betraying Eggman. Sonic broke free after a short time. Metal Sonic then fought against Sonic, Tails and Knuckles during the attack on Knothole Village but was destroyed.