Ok, so I've jumped a bit off the deep end with this one. I'm changing some things about the original story within the Akatsuki no Yona universe. Basically, AU but in a good way.
New basic storyline thing: There are more than 5 dragons, the original 4 who were chosen to watch after the king did so and then when they left, they started new clans. Dragon clans. Every Dragon clan is made up of the descendants of the original Warrior of that dragon, their families, and refugees from other clans/nations. These clans are not as isolated as the original villages; they easily interact with the other people. Each clan comes from a single dragon. Each dragon has a mark that they give to those among their clan that bear the dragons gift (Like those red markings underneath Shin-ah's eyes are the blue dragon's mark) There are two basic classifications that get broken down into more detailed classifications within the clans: Marked or unmarked. If a child if marked, it means that they have received some form of the dragon's gifts. Marked children are born that way, with the mark changing as the children mature into their abilities. An example would be a child born with blonde hair that darkens into black as the child ages into their teens when their abilities mature. Some marks are not easily identifiable until the child matures. An unmarked child is simply one that bears no gift personally. Marked children are then broken up further into divisions: there are Warriors, Guardians, Scouts, and then specialized groups based on the different abilities. There is only at most two Warriors from any clan at any time. Warriors are what I am calling what originally are the dragons in cannon, so Zeno for example would be a Warrior. Guardians are adept at survival and protection, they are the main fighters when it comes to the marked people. There are any number of Guardians. Guardians are similar to what Hak did during Canon. Scouts usually run solo missions or in pairs. They scout out any possible problems in the nation and are usually the ambassadors for the clans. Any marked person can be a Scout except for a Warrior for obvious reasons, though most who chose to become scouts do not have strong abilities because Scouting requires a calm temperament and the stronger a mark's abilities the more dragon like they are. Some marked people do not have the right mindset for scouting and chose to pick up normal trades instead just like how some unmarked people chose to pick up Guardian or Scouting positions, which is perfectly fine and accepted within the clans. There are different marks for each clan, some more obvious than others and no two clan marks are similar enough to mistake it for another. When a marked person marries an unmarked person, if they chose to the unmarked person can be given the markings of their mate. People from different clans can marry. Usually marriages are between a marked and unmarked person or between two unmarked people. It is unusual for two marked people to marry, because marked people often view each other as siblings regardless of the clan since the dragons are basically brothers and as such they act as one very big and slightly dysfunctional family. When two marked people do marry, it is normally from the same clan. Two marked people marrying from different clans often have difficulties having children because of the conflicting personalities of the dragons. Any child the who do have is either unmarked, or bares the mark if the strongest parent as a safety percaution but inherent abilities from both dragons. Like if a Warrior and a Scout from differing clans marry, any children will inherent the Warrior's markings. Cross clan children are very powerful and very protective, especially with children. These Children often become wandering Guardians after they mature into their abilities. Now then, this has all been backstory because my actually story does not start until long after. You see these peaceful times of the clans faded and a great war among the countries began. The soldiers went for the Dragon clans first and massacred them, a lot of the unmarked members managed to escape as well as a few of the younger marked children and Scouts but they were later hunted down and many of the clans were completely exterminated. This led to the situation we open into with in canon, with the Dragon villages and only the four Warriors of the remaining clans bearing any marks. The knowledge of the Clans was lost over time, and now only a handful of people even know that the clans once existed at all.
Ok, so I know this can be a bit confusing so if anyone needs anything clarified or sees anything that I forgot to explain in here just PM me and I will be more than willing to help.