They are both horror/mystery/crime stories and have a similar dark vibe. They both deal with serial killings, even in the Children of Nobody take place in the present. But in both cases the answer is in the heroes'/heroines' past.

Both of them are horror/crime/mystery stories and both deal with serial killings, past crimes and the past of the protagonists.

The best historical drama. They take place in almost the same period and they have conflicts between the princes and political affairs. And in both the famale lead works in the palace for a time. And they are really sad.