Nebula Dragons are nocturnal creatures. With the best eyesight to be found, they are often seen staring into space. Each dragon tends to observe a particular nebula and will eventually change their colors and patterns to match it. As the nebula changes over time, the dragon changes with it. The more intricate the design of the nebula, the better chance an individual has of attracting a mate. It is said that the markings on no two Nebula Dragons will be exactly the same.

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.

Vector is a rather formal Nebula whose stellar markings gleam the brightest of any of his species that come into Kiryu's possession. He is very respectful, and almost always refers to his owner as "Sir". While technically a dominant male, he somewhat distances himself from the other dragons, watching the night sky and staying on the alert for Vampire Dragon activity. Nothing can be confirmed, but it is whispered that he is involved- perhaps leading- in the movement to drive back Aszalia'xai and Akilatrai, the leading pair of the oppressing Vampire Dragons. Vector has no single mate and will breed with any dragon Kiryu puts him with, provided the other dragon will take him.