Hellfire Wyverns are so named for their foul tempers and fiery visages. Their social structure places all females above all males, due to superior physical characteristics and violent dispositions. Forced subservience of the males causes them to become vicious, petty, antisocial, and passive-aggressive compared to the aggressive and social females. However, orphaned hatchlings raised by foster parents of another species can develop surprisingly even tempers and mellow dispositions, proving that their defining unpleasant nature is, in fact, a learned behavior.

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.

Reydah, like all of his species, has a foul temper when annoyed or pushed too far, and will decimate a surrounding area in a fit of rage. However, when he isn't annoyed (surprisingly most of the time), he has a very gentle disposition, and won't harm anyone or anything so long as they don't 'push his buttons.' This is because his owner was extremely kind and patient with him when he was a hatchling, only scolding him when he really deserved it. As such, Reydah is nowhere near as mean as the other Hellfire Wyverns; staying by his owner's side and allowing her to ride on his back when she needs to get somewhere urgently or just simply wants to fly with him. His fiery patterns glow brighter or duller depending on his mood, but usually they are very bright due to the fact that Reydah is usually always happy about something. Reydah is an expert at fire breathing, creating plumes of fire shaped like all kinds of complex things just for fun, delighting the hatchlings that visit him.