Balloon Dragons are so named because they are filled with a gas that makes them almost lighter than air, similar to balloons. However, they are not prone to bursting, as they are covered in tough skin and can deflate themselves if necessary. In addition, they generally are slow moving. They use their gas bladders to float to the tops of trees, where food is more abundant. They can shift their weight from their backs to their fronts, allowing them to reach leaves and fruit.

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.

In Kui family, it's been some kind of tradition to married with SinClair family, but Ballon Kui hate it and doesn't want to do that. He even has planning some sort of fake marriage just to stop the matchmaker from happen.

All his resistance disappeared when he saw her. Ballon SinClair.

Even now he doesn't know or understand why he keeps attracted to her. While she always seem live in her own world and never notice that he always there for her, waiting for her to realize that he is exist.