One idea i heard for the Jade Court was the idea of the Faceless Abomonation, the idea being that the Jade Court are so mysterious because they do not have faces, they are nameless spirits of rage or hate they lack identities and memories of why they rage but they hate those who still have names and faces. The Jade Court then steal the faces of thier victims in hope that it would ease the pain of their existence this is fatal for the victim, so what Jade Court vampires eat is identities over hundreds of years they become less spirits of rage and more warring composites of personality.