Black Dragons are warriors. They are strong and capable in battles of force, but also ample magic users, capable of devastating opponents with their spells. Their bright eyes give them excellent night vision, which is why they generally hunt during the night.

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.

Infinity Cosmos is a dragon rarely seen on the ground. He prefers to soar up high into the sky, where the air is thin. Though he rarely eats or sleeps, he sometimes comes down to the summit of the tallest mountain to take care of these needs. While soaring through the sky one day, he thought of an important theory: how the universe began. He cannot tell anyone this theory, however, except for one special son. Infinity has a "second half", Eternity, who has a theory on how the universe will end. Although they are not mates, they planned to start a line of dragons to preserve this idea. They called together a group of Nebula Dragons to create this line, hoping to one day unlock the secrets of the universe. His mate is Harmony, his favourite Nebula of the group.