Well, that we already know. But what is more interesting is that he seems to know about the blue eye and Raven. There was a theory of him being the soul of the confined demon underground who served as an energy source all those years. It is not confirmed but it is a possibility which rose in my opinion after reading this chapter.
Meredith telling the "king" that he waited for him all this time and only held out to meet him while having the flashback of Raven, the girl and the blue eye, can't be ignored.