Queen Hong
She is the Queen of Heaven and in volume 7 she is revealed to be the Red Princess, or the Princess of Hell. Her true name being Wal-Hyang Jin. We also discover Bi-wal is Queen Hong's younger brother. She was behind Doung Young's escapade to earth and ordering White tiger and Red Phoenix to guard her. She is the eldest child of the royal family of Hell, and Ryung-Jin and Bi-Wal are her twin younger brothers (younger by 100 years, I should note.)