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.

Larxene D'Eclair, known more commonly as "The Savage Nymph", is a vision of fury and sadism. She hatched in a tumultuous period, which shaped her ideas about interpersonal relationships and how best to handle her own feelings. She eventually settled on inflicting pain on others in order to distract herself from boredom and dealing with her own issues.

Recently, Larxene has been running off-the-record missions for her hatcher at an obscure castle over in another kingdom. No one knows what she's been doing, and she adamantly refuses to say anything on the matter besides that her hatcher has sworn her to secrecy.

Larxene's nickname comes from her sadistic style of fighting, using electrically-charged claw attacks to stun her target and then go in for the kill, as well as her status as the only female in her mission group.