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.

Trevelyan, along with Agent Rose, is part of the Agensee. The story of their club's name is an odd one, but one that Rose is happy to tell to any who ask. The group is comprised of dragons who, for one reason or another, bear the name "Agent". Agent Without a Cause, a Magi, was considered for membership, but after his rambling comments about secret societies and his insistence on strict security protocols, he was politely asked to leave. Then, when that didn't work, Trevelyan chased him off. The Agensee now spends a good deal of time simply avoiding Agent Without a Cause. Rose looks at the whole situation as a sort of game, much to Trevelyan's amusement. Although he won't admit it, he is worried the strange Magi might be dangerous, and has half-jokingly declared himself Rose's bodyguard.