Promise, the theme song of the film The YingYang Master, is sung by Chen Weiting, currently one of the most popular singers in China, who also plays the character of Ci Mu in the movie. The unique voice of the singer provides an impressive expression of the emotional entanglements between Qing Ming (played by Chen Kun) and Ci Mu (played by Chen Weiting).

 “Look back through the vastness of the sea of people; The hardship along the way is confirmed, the frost passing by can also give hope to impermanence” – the lyric lines sufficiently show the destiny of separation between Qing Ming and Ci Mu caused by a mistakenly pronounced word. The fellow disciples who have originally supported each other now become the enemies because of the difference in their beliefs: Qing Ming, despite his half-human, half-demon identity, always thinks of the sentient beings, while Ci Mu is indulged in the power of sorcery. The contrasts and conflicts between the two characters are depicted on multiple dimensions by Chen Weiting’s singing with much explosiveness.

In the film, the entanglements between humans and YinYang master and between human beings are the main theme throughout the film. The relationship between Qing Ming and Ci Mu is the most complicated and difficult one to resolve – they are both fellow disciples who have supported each other since their childhood and enemies that refuse to compromise. Many audiences are reportedly looking forward to seeing how the intricate emotional changes will be played by Chen Kun and Chen Weiting.