Thunder Dragons are the masters of electricity. Their wings gather energy as they soar through the clouds, and when they clap their wings together they can create devastating arcs of lightning. They can stay airborne nearly indefinitely, landing only to sleep and breed; they catch their prey from the air and take moisture from the clouds. A thunder dragon’s roar is considered to be an omen of misfortune.

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.

Xevioso is a loner, rarely venturing below the clouds and within the sight of those he considers "lowly earth dragons." He was hatched and raised on the peak of a tall mountain, and his mother abandoned him in search of her mate as soon as he was able to care for himself. He is an incredibly proud dragon, and rightly so, as caring for himself from a young age forced him to learn and develop many skills fairly fast. Xevioso is a traveler, often going months and sometimes years before returning to his lonely mountain home. He either acts cold or indifferent towards others and is even a bit sadistic at times; his favorite game is chasing the human farmers back into their little caves by suddenly flooding the skies with clouds and small bolts of electricity on sunny days.