JKSManga
So, if the shadow ability is regarded as a human and vampire ability, and can be stolen by true dream, it must be able to be copied by the Blades? And since the shadow ability is the best tool for dealing with vampires, could the blades potentially be the largest threat the vampires have to deal with, maybe they're the ones who were killing vampires during Arthurs time as the humans had to be as powerful as the vampires to be able to kill them and the blades are the most powerful human clan.