Despite their great size and strength, Celestial Dragons are a peaceful breed named for their spectral, starry appearance. Little else is known about them, as they spend the vast majority of their lives partially phased out of the plane of existence through the use of powerful magic. Celestial Dragons are thought to assume their corporeal form only long enough to reproduce or to die; the rest of the time, they resemble living, breathing constellations, impervious to all physical and magical harm.

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.

Like all of his kind, Iduen and his motives are shrouded in mystery. He manifests to interact with other dragons and occasionally humans in the Southern Continent, his purported birthplace. There he talks to anyone he finds about lofty topics like politics and the nature of reality. He is easily moved by acts of perceived injustice and will often "avenge" those who were mistreated, making him a bit of a guardian entity to the towns he roams.

Iduen does not talk much about the plane he lives in, saying "It's really not much. Just a bunch of others like me and raging pointless debates. We make jokes, but no laughs to them. We make songs, but no one dances to them. We write poems, but one cries. The real sentience is here, in the real, flawed world." This about the most direct response anyone has gotten out of him regarding the celestial plane.