The Radiant Glow are a subsect of the Darwin religion.They experiment on captured animals or people and exposing them to massive amounts of radiation.They let the radiation get into their victims blood, after a sufficient amount of time they drain the blood out of these people and inject it into whatever they happen to be experimenting on (Usually Zeds).
They then send these experiments out into the world. They are people that want to finally complete Darwins designs in a horribly unsafe fashion.
Their leader is rumored to be a severely mutated Free Radical. However survivers that have escaped their kidnapping have never seen his or her face.
More Information will be added as it is collected