Four thousand years ago, when the ancient civilization was in a flourishing period, they created a destructive weapon, called the Gizoid, in the form of a robot. But as the fading invaded, with wars everywhere, the Gizoid was buried. However, it had been unearthed by Professor Gerald Robotnik for the aim of later research. Nevertheless, it was built by ancient technologies, which is the point that made it difficult for him to analyze and even unable to operate, so he decided to abandon it at Emerald Beach. Sonic then discovered and used the emerald to make it work again. But later, he found it is a weapon programmed to destroy, and its imitating ability makes it even become more dangerous. Dr. Eggman has researched and learned about this. As the hatred arises, he wishes to awake the true nature of the Gizoid.
