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.

Vivere Umbra is a typically mysterious Shadow Walker dragon. Although he has many friends among the other Halloween dragons in the Cave, none know that he once had a friend of an entirely different kind, a neglected Electric Dragon hatchling who ended up in his care. This hatchling's name was BRVR, and for a while he was Vivere's only friend, for the Shadow Walkers were shunned by the other dragons in the Cave. BRVR and Vivere were inseparable. However, Vivere began to realise that there were other dragons who were considered outcasts because of their breed, like the Black Marrow dragons, and he began to make friends among them. Looking after BRVR seemed less necessary and more of an annoyance, so eventually Vivere simply left him in his cave. He didn't return until some weeks later, when he was horrified to find that BRVR had become a deranged killer, driven insane by the torment of being left alone and abandoned by his only friend.

Vivere will never quite be able to forget BRVR.