Shadow Walkers are a strange breed that possess the ability to slip between the planes of reality, becoming immaterial. This allows them to hide in the shadows, either hunting from the concealment of near invisibility or evading enemies. Though they become corporeal to mate or to eat, they spend most of the rest of their lives walking in the shadows. Shadow Walkers are wary creatures, though on dark autumn evenings when the leaves fall to swirl in the chill, rain damp air, they may be seen drifting out from the shadows.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

If Krypton the Soulpeace is considered mysterious, then his brother Radon has got to be more than a mystery. Not one member of the Periodic Clan has seen more of him than his head, peeking out from behind a tree or bush, which is often clearly too small to conceal a dragon's whole body, stare fixed on whoever is passing by. He won't speak to anyone, either, and it's uncertain whether he is even able to. His presence always leaves quite an uncomfortable atmosphere; remarkably, even the constantly chattering group of Luminae called the Catalysts will go silent when Radon is around.