Behind The Mask (Akatsuki No Yona Fan-fic)

HERE'S THE NEXT ONE!
A promise. It was all it took to bind the Dragons together. Blue, Green, Yellow, White, Red, and one more. One who'd disappeared soon after the Red Dragon's death. Many say it went into hiding after murdering the Red Dragon, others say the loss of the Red Dragon had been too much to bare for it to continue on. No one knows for sure, that reason died along with the original dragons. But, what happens when a masked woman appears before Yona and Hak as they attempt to run away from Yona's home? What happens when the masked woman attacks their pursuers then turns her weapon onto them? Yona feels a wave of recognition towards the masked woman, but how? More importantly, who's the woman behind the mask?