As KBS's revenge melodrama Nice Guy approaches its end, fusion sageuk Jeon Woo-chi prepares to launch. It stars Cha Tae Hyun, a Taoist wizard from a fictional nation of Yuldo, who lives a double life to avenge the death of his mentor, Hong Gil-dong, and his lady love, Hong Mu-yeon (played by UEE). Mu-yeon is Hong Gil-dong's granddaughter and a princess of Yuldo. She falls prey to dark Taoist magic that makes her lost her emotions and commits a murder. However, the spell weakens once a month where she can return to her former self.