Gwi is a major antagonist in 2015 South Korean television series Scholar Who Walks the Night. Gwi is a centuries old vampire who lives in a dungeon within the royal palace and works with the prime minster who has always sought power against the King. Gwi was indirectly responsible for making the Prince's good friend Kim Sung-yeol a vampire, is also the murderer of Sung-yeol's fiancee, Myung-hee and rules over the king, whose ancestors sought Gwi's assistance in the creation of Joseon. He launched a coup against the king and became king himself.
Not known of his past, Gwi was a cruel and sadistic vampire who enjoyed his victims suffering or turning them into vampire servants. He also murdered members of royal family including Queen of Joseon. Crown Prince Junghyun and his best friend Kim Sung-yeol began writing books about a vampire sucked blood of King's concubines. Sung-yeol was warrior who fought with assassins and got married to his sweetheart Myung-hee since childhood. Gwi ordered the King to find him meals and called his guards foolish people. He learned that the Crown Prince exposed him as vampire.
He also murdered Prince Sadong. Gwi taunted Sung-yeol for Myung-hee's death,