The All-High Gods were a group of entities which took over Dellah.
These gods were beings of advanced power. They could take over and possess beings, in the form of a religious fervor. They fed on belief, and when deprived of that, each other. They had no power over artificial life, like Synthoids.
In 2595, the All-High Gods took over Dellah, turning the people into religious fanatics. Anyone who disagreed was killed or forced off the planet. One God possessed Emile Mars-Smith, but he was taken off planet and starved it by trapping himself on an uninhabited planet. After the Gods had taken over Dellah, they decided to go for Thanaxos by inviting an official delegation. One God possessed Prince G'jimbo and then returned to Thanaxos, causing a religious revolution when he returned. The God was later defeated by the God within Emile. (PROSE: The Mary-Sue Extrusion)