The Priestess was the mysterious woman who give Historia her powers and immortality.
The Priestess had blonde hair and blue eyes. She is average height with fair skin and a slender body.
The Priestess is very mysterious. She showed to be kind and helpful towards people. She had empathy towards those who are in pain (Historia being the example). She can be very generous towards anyone who is in need of help, giving them powers. However, she can firm and strict if that person is being immature and using their power recklessly. Showing that she can scolded them for being foolish. Still she can be very forgiving even that person can immature at times.
However, it's revealed that all of that was a facade. The Priestess was shown to be mentally unstable because of her immortality. She managed to tricked Historia into believing that she cared about her. She was also shown to be suicidal. This showed longed for her death.
Although, it's unknown how she got her immortality but she lived years ago.
The Priestess met Historia when the latter was a child.
Although, it's not shown, The Priestess must likely had the same powers as Historia.
- The Priestess is the second old human in the series.