Another historical drama about the corruption of power. Also, they are both about the strength of the people, good over bad, and the struggle for justice.
I find that even though the plot lines may be different, one being about a princess and one about a vampire, they have very similar characters and character relationships.
The female lead in both dresses up as a male, for their survival, in the early part of the drama. They are both bright and friendly, though, Jo Yang Sun isn't as thoughtful and clever as Jeong Myeong. Both have a strong fate with the inner workings of the palace.
Both male leads are kind and caring, and will go to the lengths to protect their leading ladies. Their caring love is what makes you heart race while watching the drama. Difference though, Kim Sung Yeol is a vampire and Hong Joo Won is a bashful scholar (well he moves up in rank through out the drama) .
The royals in the drama are similar too, where, as much as they want to fight the corruption, its extremely difficult. In the process, they lose their original goal and stray. Their mission throughout is continuously remind themselves of purpose and try to find the right retainers.