Duchess Byung-Hee is the current leader of the Unknown province and head of the House of the Crow. She is actually the last remaining direct line member of the house with no named heir. It is, however, likely that should nothing change, she will name one of her younger cousins as her heir.
She is married to Lady Suk Dahae, a kumiho who chose to give up her task of ferrying the dead for the time being to instead be with Byung-Hee.