K-Drama villains are often portrayed by actors and actresses whose previous roles have painted them in a positive light.

Sung Joon gained notoriety as the sweet tempered boy-next-door through his roles in “I Need Romance 3” and “Discovery of Love.” However, his dual role as hypnotherapist Yoon Tae Joo and the sociopathic kidnapper Lee Soo Hyun in “Jekyll, Hyde, and I” (Jekyll, Hyde, and Me) has shattered his cultivated image as the perfect boyfriend.

“Jekyll, Hyde, and I” continues to flounder in its ratings war with “Kill Me, Heal Me” but Sung cannot be blamed for the lack of interest from viewers. He is captivating as he attempts to evade the police while slowly driving Jang Ha Na (Ha Ji Min) further into insanity.

Soo Hyun interacts with the other characters in a way that is truly sadistic. Before he reveals his true identity, he toys with Seo Jin (Hyun Bin). He is intrigued by the appearance of Robin but maintains his plan to extract revenge against the heir to Wonder Land while eradicating Ha Na, the witness to his crime.

He displays his own mental instability through his statement, “Seo Jin doesn’t have a twin. Perhaps, was it you back then?” From this point, he begins to abandon his pretense as a well-intentioned physician.

In episode 10, he contacts Seo Jin and requests a meeting with him at the Ghost House, a location in the amusement park that is visually disconcerting. As children, Seo Jin and Soo Hyun had an unpleasant experience in the house of horrors. Soo Hyun ruthlessly incorporates this into his revenge plot.

As exemplified in “You Who Came From The Stars” and “Pinocchio,” there is nothing scarier than a man whose life is driven by revenge. Sung Joon has demonstrated his boundless versatility as he continues to help the plot of “Jekyll, Hyde, and I” unfold.