Effigies are essentially humanities, but their powers are significantly reduced. They are constructs made of the Dark Soul, and do most have nearly the same amount of essence as a regular Humanity In Dark Souls 3, it is possible that the player character is not human, and is rather a previous Lord of Cinder, risen like the rest, for your own purposes. That is implied, anyways, when an Ember is used. It gives you a 'Lord of Cinder' state, and it most likely empowers your player character with the last remaining power of the First Flame. Alternatively, your character is completely human, and the Embers only give a fraction of the power the Lords of Cinder hold. It is mainly speculation at the moment, and I'm sure this question will be able to be answered better in the future.