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.

Unlike most Blacks, Dimmu's eyes are blue, glowing green to yellow when he is angered, and his underside is orange rather than pale yellow. He doesn't seek trouble, but if need be he's a tough opponent. In battle he focuses more on his powerful magic than physical strength; his mother and grandmother may be black dragons, but his father is a powerful Magi.

Dimmu uses his magic mainly to hunt, which he does not only for food but also for fun. The local wildlife was so severely damaged by his 'hobby' that he even turned to poaching on the lands of the Guardians and Silvers, leading to the necessary clashes between him and Shoogle. Those usually result in Dimmu minding his own business for the next few years.

Despite his rough appearance he is quite a peaceful fellow, sometimes even using his magic to heal others, just like his White grandfather. However, don't insult him, or his black blood will boil and you shall suffer the consequences, feeling the full strength of his spells.