Dragons have existed for more than a hundred thousand years. There were 5 dragons pertaining to the Gaea's elements. Earth, wind, fire, water, and spirit.
The dragons lived in harmony all except for the Fire and Water dragon. The polar opposites battled everyday shedding their own blood.
As the years of fighting grew they began to dwindle and weaken in age. It was decided that each dragon would embed themselves within a human, and be reborn from the host's offspring.
They chose rulers from every corner of Gaea, and from there they picked up from where they left off.