What is the true identity of the solitary Raven Consort?

The Raven Consort is a special consort living deep in the inner palace who, despite her title, does not perform nighttime duties for the emperor. Some who have seen her say she has the appearance of an old woman, while others describe her as a young girl. The Raven Consort's name is Shouxue. She has the ability to use mysterious arts and will accept any favor asked of her, whether it is to find something lost or to curse someone to death.

The current emperor, Gaojun, visits her one night to ask a favor. Their meeting exposes a secret that will turn history on its head...

[Source: Crunchyroll]