So my idea is that I would write a story about the tale of the nine-tailed. And instead of Ji-a having the serpent inside of her it would be my own character where the serpent and herself made a deal. The story starts on episode 15 when Tarry the other serpent was going to fall into the Samdocheon (river of death) river with Yeon. However my character stops them and tells them that she has the other serpent half inside of her already.
So that way it would be a good ending or a bad ending depending on the characters choices they make in the story.