Esdras is a member of The Anointed Legion and the brother of Perpetva. An item description reveals that Esdras is thought to have gone insane due to trauma at the eyes of his companions from the Legion. This is because he is seen talking alone as if his sister, Perpetva, was present. She died in battle time ago.
It is confirmed that sometimes, Esdras is actually able to see Perpetva in the form of some sort of angel, who is constantly watching over him. The Penitent One seems to be the only person who can also see this "ghost". It was revealed that she is a lie created by the Miracle that seeks to manipulate Esdras into stopping the Penitent, and not Perpetva herself. However, the actual Perpetva can be found in a hidden area from Echoes of Salt.