Here's an idea, this could be the embodiment of Death itself in Book of Lust. Given her dress is like the western Grim Reaper. As a carrion bird, ravens also became associated with the dead and with lost souls. In the Qur'an's version of Cain and Abel, a Raven taught Cain how to bury his brother Abel after he murdered him. In Seberian epic poems, Ravens are associated with Death - more specifically with an aftermath of a bloody or significant battle.
Here's an idea, this could be the embodiment of Death itself in Book of Lust. Given her dress is lik