Originating from a single species that thrived in ancient times, Xenowyrms have become an incredibly diverse breed whose appearances vary depending on their habitats. Each Xenowyrm subspecies is heavily reliant on the power of a different type of mana, making them powerful magic users. Thalassas are a unique variety of Xenowyrm in that they are the only subspecies known to dwell in marine environments. Their porous skin and slender build are perfectly suited for the aquatic terrain, but they can only survive for short periods of time on land. Powerful users of water magic, they can create large waves and alter currents with a simple thought.

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.

Hyoryu is particularly sensitive to the magical affinities of other dragons, and over the years has become attuned to the particular patterns and feeling of various species' elemental auras. He can sense the affinities of dragons within a certain radius, describing the sensation as either a weight or an itch upon his consciousness. This ability makes him ideal as a convoy attendant, as he can usually sense an approaching threat before he sees it. However, Hyoryu finds crowds incredibly overwhelming, and spends most of his time by himself in his undersea dwelling.