Main •
Kim You-jung as Hong Cheon-gi • Lee Nam-kyung as young Hong Cheon-gi : A red-eyed man who lost his sight due to a mysterious accident while attending a rain-making ritual in his childhood. He survived due to the power of the Demon King, and lives a new life as an astrologer, while preparing to take revenge on the royal family, since they are responsible for making his life miserable. •
Gong Myung as Grand Prince Yangmyeong (Yi Yul) • Kim Jung-cheol as young Grand Prince Yangmyeong : The third son of King Seongjo, a leisurely prince who is known to be an expert at painting, calligraphy and poetry. He seems to have a free spirit that is full of romantic qualities, but also has a deep sense of loneliness inside. •
Kwak Si-yang as Grand Prince Juhyang (Yi Hu) •
Park Sang-hoon as young Grand Prince Juhyang : The second son of King Seongjo, a man who wishes for the throne he cannot have. In order to become a powerful king, he wants to become possessed by the Demon King.
Supporting People around Hong Cheon-gi • as Hong Eun-ho : Hong Cheon-gi's father, a former painter at Gohwawon (Royal Painting Bureau) who lost consciousness during a major event 19 years ago. •
Kim Kwang-kyu as Choi Won-ho : Head Master of Beak-yoo Painting Society who takes care of Hong Cheon-gi as if she were his own daughter. •
Yoon Sa-bong as Kyun-ju : The person in charge of housekeeping of the Baek-yoo Painting Group. She treats Hong Cheon-gi like her daughter. •
Hong Kyung as Choi Jung : He is the most famous painter in Gohwawon and has a talent for painting portraits. • Hong Jin-ki as Cha Young-wook : Cheon-gi's best friend and fellow painter at Baek-yoo Painting Group
People around Ha Ram •
Kim Hyun-mok as Mansoo : Ha Ram's servant •
Song Won-seok as Moo-yeong : Ha Ram's escort warrior who understands martial arts. He follows him like a shadow, protecting Ha Ram with the grace he received from him in the past. • as Mae-hyang : A
gisaeng who helps Ilwolseong of Wolseongdang.
People allied with Prince Yangmyeong •
Jo Sung-ha as King Seongjo : The 4th King of the Dan Dynasty •
Ko Kyu-pil as Go Pil : Prince Yangmyeong's servant •
Jang Hyun-sung as Han Geon : A master of landscape and scenery painting and an expert at Gohwawon. • Kim Joo-young as Lee Hyun-mo : A government official and Prince Yangmyeong's ally.
People allied with Prince Juhyang • as Mi-su : She was once the chief royal shaman and Seongjucheong's 4th head priestess, but got banished from the palace and now works for prince Juhyang. • as Ahn Young-hoe : Prince Juhyang's adviser. • as Prince Juhyang's escort warrior
Gods and Deities •
Moon Sook as
Samshin : The goddess of life, who protects Ha Ram and Hong Cheon-gi. •
Jo Ye-rin as Ho Ryeong : The Tiger Spirit of
Inwangsan, the guardian deity of the King's Palace. • as Gan Yun-guk/Hwacha : Former Gohwawon expert who got possessed by Hwacha, a goblin who lives on the energy of paintings.
Others • Kim Geum-soon as Wol-seon : Current chief royal shaman, Seongjucheong's 5th head priestess • Jang Won-hyung as Shim Dae-yu : A mysterious painter who always wears a bamboo hat, thus getting the name "Shim with bamboo hat". • Kwak Hyeon-jun as Kang Hee-yeon : A painter from a wealthy aristocratic family.
Special appearance •
Han Sang-jin as Ha Seong-jin, Ha-ram's father, former chief officer of the Martial. • as King Yeongjong, the 3rd King of Dan Dynasty • as Ma Wang: the Demon King (voice appearance) •
Choi Jong-won as Ha Dam (Ep 11–12, 14–15) : A mysterious prisoner at stone prison, later revealed to be Ha Ram's grandfather. ==Production==