Very few are human anymore where I am from. At least not enough to matter.
It is too complicated. I will keep it brief: Great Ones - Gods - were discovered. Their blood was used to heal the sick and dying. Unfortunately humans are not meant to use the blood of the Gods, and people grew ill in the head. In Yharnam, they turn into beasts. It is an agonizing and slow transformation into madness. In Cainhurst, we had a different strain of God blood. We drank it, in exchange for immortality. Someone I spoke with earlier compared it to a creature commonly known as a vampire? The Church calls us Vilebloods. The Yharnamite plague of beasts was an accident, but we heretics at Cainhurst chose our descent. To further our immortality we began to prey upon the hunters of Yharnam exclusively.
I left, many years ago, when I was of an age to be disgusted with what my family had done. They believed they were keeping me safe, but I will belong to no community which sustains itself on the lives of innocents.