Nexus Dragons are massive, volatile beasts surging with magical power. Each half of a Nexus Dragon’s body is infused with fire or ice mana, and it is believed that the unstable nature of these paired elements drives the dragon mad as it grows in size and strength. They are strict carnivores, preferring to feed on dragons and other creatures that naturally possess magic in order to bolster their own stores. As Nexus Dragons age, fire and ice mana crystals grow all over their bodies, enhancing both their power and viciousness.

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.

Two-headed dragons are unique enough to deserve a separate classification from ordinary dragons. They have two necks, two brains, two mouths, but one stomach and one main body. The two heads usually work together, but there are times when they will fight each other, snapping back and forth. Their unique anatomy prevents them from breeding with single-headed dragons.

Hasei is rather prone to irritability, and can often be found sulking near natural springs that have mana deposits at the bottom. She will defend these areas viciously, often marking her territory with swathes of burned and frozen foliage, and only move onto another place once she has consumed all the mana in the spring and eaten all the magical creatures living in it. Her family has endeavored to set aside some areas in the mountains for her use, and keeps a stash of mana crystals for Hasei to gnaw on when she's between locations.