The Fallen is based off a creature from the multiplayer horror game Damned and from the Weeping Angels seen in Doctor Who.
It is an angel statue covering its face. Folklore states it cannot move if you keep eye contact with it, but The Fallen can still move when watched. In game, it moves like a chess piece. Its hands move slightly when attacking.
Her ability is to place down a decoy of herself, which can be useful in many situations. But if a player or group of players run into the decoy and touch it, they will trigger an alarm and the person playing Fallen will be able to see an outline of the affected players through the wall. She can also teleport back to the decoy at any time.