What the Chelgrian-Puen, the gone-before, did with their still applicable super powers was to build heaven. They made matter of fact what had until then required an act of faith to believe in. When a Chelgrian died, their Soulkeeper device was the bridge that carried them across to the afterlife.
This meddling in, or simple contact with, the unsublimed Chelgrians is what makes them unique among galactic civilizations.
