After Imperator Ix took the Chaos Emeralds and the Master Emerald from Sonic's world, he placed a Chaos Emerald in each colony. For some reason, he placed two Emeralds on Voxai Colony Beta and Voxai Colony Alpha. After the Overmind obtained the two Emeralds, they treated the Emeralds and changed them into Great Emeralds. But the Overmind then became mad with power. Originally, they were kind and asked their people to accomplish great things, but when they Chaos Emeralds came, they "no longer asked, they demanded." Sonic and his friends came to Voxai Colony Beta, one of the local residents, Thebes, told them about the Overmind and Great Emeralds. They tried to reach a portal that would take them to Colony Alpha, but one of the Overmind's elite guards, Thelxe cut them off and fought Sonic an