Priestess of the Alien God

The mysterious unnamed woman appears during the Cosmos in the Lostbelt scenario of Fate/Grand Order.

Background
The identity of the woman is unknown. Before Chaldea is attacked, she is shown to be present in the Lost Room.

Personality
The woman remains silent and mostly emotionless. She is shown to react to seeing Ritsuka Fujimaru's destroyed room by closing her eyes, and she reaches her hand out to Mash in the opening.

Abilities
The woman is shown to be present throughout Chaldea without anyone noticing her.