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.

When Papa Midnight tried to open a gate to the Netherworlds on All Hallow's Eve, the only dragons standing against him were his own son Brother Voodoo and the dragoness 'Walks in Between'. The two fought a losing battle against Midnight as he summoned Zombie upon Zombie to his side until more and more Shadow Walkers came through the gate to help their sister and the young Magi.

Aidan is one of the Walkers who stayed with the clan after they defeated Papa Midnight to help forever protecting it from danger. Some claim that he was a Golden Wyvern once, who slowly faded away from the physical plane after no dragon seemed to notice him, in turn becoming a Shadow Walker. Aidan never denies nor confirms this, but only reminds the others with a sad smile, what loneliness might do to a dragon, encouraging them to take care of each other.