Caligene Dragons have long been considered omens of death—reinforced by the skeletal markings on their bodies. They exert a malignant force on the world around them, causing other living things to slowly waste away in their presence. Caligenes favor the seasons of summer and autumn, disappearing entirely from the forests they inhabit during winter and spring. These malevolent dragons are physically weak, though this is countered by their natural stealthiness and alarming speed—enabling them to close in on large targets quickly and silently to create ambushes from which prey cannot escape.

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.

Undazio is the dashing leader of the greatly feared Shades, a notorious group of reapers who use their deadly abilities to influence even the most powerful dragons to do their biding. This tightly knit circle of dragons almost exclusively consist of Caligene dragons (with the exception of Dasain's son) so they heavily rely on intimidation through a slow and painful death. The Shades tend to be swayed by pure gold and flawless garnets, so when their services are hired it is no ordinary event. Some of their most famous appearances include the War of Vampiric Divine (The conflict between those unholy and the Guardians) where they "Convinced" the Guardian of Soul that the existence of the Vampires had nothing to do with demonic beings, and The Clash of the Skulls (The feud between the Slingers and the Two skulls) where the only living heir of the Two skulls mysteriously disappeared, and the Slingers gained a huge influx of information from "Feathered ghosts", as many would call them.