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.

Mysten is a very mysterious dragon. She is an excellent fighter who is most active at night. She's also quite adept at magic, but she prefers to use stealth and speed in battle. None of her victims know she's even there until it's too late. Mysten has a strong sense of justice and will only attack someone if she thinks they are evil. When she's not fighting, she is either training herself or studying ancient scrolls. Whenever other dragons ask her why she does these things, she'll just reply that it's her business, not theirs.

  Ever since they were young, there has been an intense rivalry between Mysten and Hydro Boy. Mysten will often warn ships if they are approaching Hydro Boy's territory and will guard them from his attacks. Whether she does this to protect sailors or to get the better of Hydro Boy is unknown.