Gong Yoo melted hearts playing the heartthrob goblin Kim Shin in this drama series hit, but his character wouldn't have existed without the evil Park Joong Heon. Played by actor Kim Byung Chul, Park was the man responsible for Kim Shin's death centuries ago when he was a general. Park was the servant to a young king and fed him envious ideas that Kim Shin was trying to dethrone him. Fast-forward more than 900 years later, just as Kim Shin returned as the Goblin, Park returns as a demonic spirit to get revenge and haunt Gong Yoo and his bride. His excellent acting and ghoulish makeup -- with his trademark dark, purple lips -- were unforgettable!

Actor Jang Mi Kwan's first role in a drama series was in "Strong Woman Do Bong Soon," as a psychopath who kidnapped, tortured and killed young women. The serial killer's rage towards women streamed from his mother's physical abuse when he was a child g physical abuse from his mother as a child and rejection from a woman he confessed his love to. The model-turned-actor hid his handsome looks behind a creepy, white mask for most of the drama, which made his role even more chilling. In an interview, Jang said he had watched Christian Bale's acting in "American Psycho" for inspiration. He definitely nailed the role!

Actor Dong Ha was applauded for his role as a serial killer named Jung Hyun Soo who killed people out of revenge for his first love who was gang raped and murdered by his friends. But spoiler alert -- turns out Dong Ha was right there with the perpetrators during the gang rape. Dong Ha's role was especially filled with twists and scary surprises because he played a serial killer with amnesia.

Choi Tae Joon usually plays the personable, charming boy-next-door, but he showed a completely different side himself playing the serial killer Choi Tae Ho. His big, round eyes would make your heart melt when he's smiling, but his strong, cold gazes in this drama sent chills down the spine! A drama about a plane carrying 47 passengers, including 9 figures in the entertainment biz, that crashes and leaves them stranded on a deserted island. Choi Tae Joon, a former idol star, plays the villain who only looks out for himself and is responsible for the mass murder on the island.

Actor Kim Jae Wook played the psychopathic, serial killer, Mo Tae Goo, who is convinced he is doing the world some good by killing off sinners. Mo Tae Goo was extra creepy because when he's not on a killing spree, he is a well-mannered, heir of a wealthy family and one you'd never think to be so sick in the head. Kim also said he drew inspiration from Christian Bale's character in "American Psycho." The actor revealed that playing a psychopath had an emotional toll.

Yang Se Jong was mind-blowing because he actually played dual roles in this thriller drama. Actor Yang Se Jong plays the role of two clones who were both at the site of a kidnapping of a detective's daughter. The evil clone, Sung Hoon, kidnaps, tortures and kills people, but frames his innocent brother for the crimes. Yang Se Jong truly wowed with his ability to play both the sweet, angelic and villainous character simultaneously.

Another stellar actor who played dual roles is Uhm Ki Joon. "Defendant" is about a top prosecutor who was wrongfully convicted of killing his wife and kidnapping his daughter. All that is actually perpetrated by Cha Min Ho, played by Uhm. Cha Min Ho is one of the twin brothers of a wealthy chaebol family. He is sick in the head and is able to get away with murder because of his wealthy background. He is as evil as a person could get -- he killed his twin brother and frames it as suicide, he leaves his father to die on the ground and goes on a killing spree with no remorse. But as evil as he is, Uhm was so stellar at this role!

2PM's Junho was praised for his role as the villain Seo Yool, a prosecutor who is hired to become the new director of a company. Seo Yool is the epitome of the rude, condescending boss who does not cut his employees any slack, and runs a company filled with corporate corruption.

Portrayed by Heo Joon-ho, Dae Mok's appearance is neither villainous nor evil, but rather warm, kind, and accommodating. This works in his favor as he is sharp and manipulative of those around him. Dae Mook serves as the leader of Pyunsoohwe, a cult-like group that has taken control of Joseon's water supply. Dae Mook and the Pyunsoohwe have control over the royal family and want to induct Crown Prince Lee Sun to the throne for personal gain, earning him a spot as one of the most devious villains this year.

Kim Ji Soo played Queen Jiso in the star-studded and much anticipated Hwarang. Queen Jiso is another multi-dimensional villain whose intentions were not necessarily to hurt others. Because she fled palace life in her youth, she has an ongoing need to protect her son. Her attempts to protect her son and the throne led to the subsequent death of many innocent people.

Portrayed by Kwak Si Yang, Baek Tae Min is deeply jealous of his childhood friend (played by Yoo Ah In). Baek Tae Min is conniving and manipulating and has the tendency to carelessly put people in danger. Though Kwak Si Yang did an excellent job portraying the villain in Chicago Typewriter, he does not necessarily play the villain in most dramas! In fact, he's generally known for playing sweet roles! Impressive performance!

A Joseon King portrayed by Kim Jisuk, King Yeonsangun is easy to hate and easy to cast a lot of disdain towards. Just the way he treats his subordinates and innocent people alone is enough to make your blood boil! Kim Jisuk, like Kwak Si Yang, usually does not play the villain, but does a spectacular job that surprised netizens and k-drama fans alike! It seems that cold and villainous come naturally!