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.

Firebird Heart was one of the Hellfire Wyverns who were orphaned as eggs, but he was orphaned in an unusual way. The fate of his parents is a mystery, and as an egg, he was partially encased in igneous rock after a volcanic eruption. However, the multiple lava flows that followed managed to incubate the egg, and Firebird Heart eventually hatched. He was given his name by the humans in a nearby village, who saw the dragon's apparent birth from the volcano and briefly mistook him for the mythical Fire Bird.

Firebird Heart often wonders what became of his dragon parents and if they even miss him. As a result, he rarely travels far from the place he hatched, just in case they'd come searching for him one day. As a result, Firebird Heart often indirectly serves as the protector and guardian of the humans who gave him his name. In time, he encountered Night Puca, who was also searching for her long lost father. The pair bonded over their mutual desires, and things snowballed from there.