Dragon Realm is a realm or other world with dragons, and the people who accidentally were sucked in it. This realm is mixed with many different dragons, but the dragon belong in specific groups. Also, the dragons are divided into 30 sections with millions of dragons in the realm. The leaders of those sections are the people who were sucked into the realm or the dragons who weren't tamed yet. Each person defeated the head dragon of the section in order to obtain the lead of the sections. There are 10 sections that belong to the humans, and 20 that belong to the dragons.
Air dragon are dragons that roam and dominate the air. They are able to fly even without wings, wings just make them faster and stronger. That goes for the humans as well, when they tame and it is sealed inside them, the dragon's genes are in the human, so therefor, the humans can fly without wings. The air dragon specialize in long range combat, for example, their Kiro has wind, oxygen, lightning, and anything else that is in the air. Air Dragon or Sages, Kiro can blow mountains away if powerful enough. These dragons and people are like the archers of a group, and have complete dominance over air creatures.
Water Dragon's or Sages control the power of water and the creatures in it. A water Dragon's or sages Kiro is composed of water characteristics, like water vapor, ice, and other characteristics of water. The water dragon or sages can become transparent also. This is a technique called Camouflage of the Dragon which allows the dragon or human to be transparent or not able to be seen. They can also make anything infused with their chakra transparent. That's why this group of people or dragons are call assassins of the group.
Land Dragons or Sages control the power of land elements, like earth, grass, and other elements on land. When they shoot their Kiro, like the others it combines the elements making it powerful enough to blow hole through some the hardest and thickest things. Also they have control over the creatures of land and have a technique similar to Dragon Art: Dragon Scale Covering, call Dragon Art: Land Dragon Skin, this covers them in a very hard armor, harder than Scale Covering. These dragons or sages are the warriors of the group.