Morin was reborn into the super god-level civilization of the Protoss. Everyone was a god. As long as they matured, they could find their own believers. The more believers they had, the higher their level, and the stronger the corresponding Protoss.
Morin’s believers were the Zergs that he had developed himself. He had broken the inherent hierarchy of the Protoss and led the Zergs to become the most powerful god of the Protoss.