Mecha Sonic is one of the five main villains of the Mecha Saga and the weakest of the Mecha Quartet.
Mecha Sonic is a cruel and cold-hearted killing machine who loves to see people suffer and cares for nobody whatsoever but himself. He also seems to view himself as a god. He views his opponents as being unworthy and do not deserve to have the power of the Chaos Emeralds or even live. He shows much hatred toward Sonic and will stop at nothing to destroy him.
Mecha Sonic is incredibly fast and strong and uses martial arts style attacks in battle. He also possesses a machine gun and missile launcher in his arm although they are not used quite as often; the machine gun seems ineffective on his foes in many cases due to speed or defense, but the missile launcher is devastating to everyone, even himself. Mecha Sonic also uses energy beams and blasts in battle, the strongest of which must be charged up before use. Being made out of metal, Mecha Sonic has impressive defenses and can recover from most attacks rather quickly. The only attacks so far that can deal decent damage to him have all been fire based, such as when Mario used a full power fireball as Fire Mario on Super Mecha Sonic he was stunned cancelling a would be fatal attack. Mecha Sonic is capable of flying at will due to built-in jets and can remain airborne for an unknown length of time, perhaps indefinitely. He can also roll into a ball and spin around in the same manner as Sonic, a technique he uses for attacking, defending, and mobility. Ever since Sonic Heroes, Mecha Sonic has been able to analyze and copy the abilities of other fighters. So far he has demonstrated Sonic's light speed attack (allowing him to move so fast it seems as though time stands still, although it must be charged before use) and Shadow's Chaos Control and Chaos Blast techniques. Mecha Sonic can use the Chaos Emeralds and the Master Emerald to power up and transform into his super forms, Super Mecha Sonic and Metallix.