Bright-Breasted Wyverns are a breed of dragon easily recognized by their bright red markings. They are a small breed, only the size of a full-grown man. However, they have developed poisonous barbs on their feet to make up for their size. Their coloration is used to warn off potential predators of the danger, and is also used to attract mates. They are very social, and can often be seen preening in large groups.

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.

Chief messenger for Cheimon Castle, Lumen spends each Friday and Saturday flying back and forth between several kingdoms and Cheimon Castle. When he's not carrying important mail (or love letters from his human Aero, she still doesn't know where they disappear to,) he's socializing with his friends, contending in friendly races around the castle towers; or napping in the courtyard fountain, head laying out on the ground.

Lumen is the perfect messenger, nobody will try to steal documents with the threat of being horribly poisoned from Lumen's barbed feet and can easily fly though windows with his smallish size.