Actor Kim Seon-ho described taking on the role of a cold-hearted elite agent in "The Tyrant" as a "scary" experience, but said he is eager to face more challenges that will help him become a versatile actor across genres.

"The Tyrant" follows the story of individuals vying to secure the last sample vial of the Tyrant Project, which endows living organisms with immense powers.

Kim portrays Director Choi, the hard-hearted head of the National Intelligence Service, who is determined to see the Tyrant Project succeed.

The role represents a new direction for Kim, who has primarily earned his star status through portrayals of charming sweethearts in romantic comedies such as "Start-Up" and "Hometown Cha-Cha-Cha."

"I couldn't remember ever playing a character so composed — one who remains detached while observing the essence of events and making deliberate decisions," said Kim during a group interview held Monday.

"In the past, I often played characters who openly expressed their emotions. I’ve never portrayed someone whose feelings leaked out in a subtle fashion. This time, I concentrated on how to make Director Choi's wordless moments feel as impactful as possible," he said.

"(In acting as Director Choi), I aimed to portray the weight of silence. I thought about which expressions would be effective when he isn’t speaking and how best to show that this character is being provoked, without saying a word," said Kim.

"The experience of playing the role of Director Choi was definitely unique, compared to depicting my previous roles," he added.

According to Kim, playing Director Choi was a "scary" experience.

"In fact, I was scared (to portray Director Choi). ... I worried about how I would rise to the challenge and how the character would be perceived," he said.

However, Kim said that he was able to overcome his fears of taking on a drastically different role with the help of Park Hoon-jung, who directed the series. "The Tyrant" marks Kim's second collaboration with Park, following their work on the crime film "The Childe."

"Park and I grew closer after working together on 'The Childe.' Our communication became more efficient, allowing me to quickly understand what Park needed from me, whether it was dialing down my energy or intensifying it," said Kim.

When asked which type of acting — light comedy or hard-boiled action — he feels is more suited to him, Kim said he is still figuring it out.

"I feel I am still more accustomed to romantic comedy acting, but I constantly see areas where I can improve in all of my performances," said Kim.

"So instead of concentrating on what types of acting might be suitable or unsuitable for me, I feel that there's value in learning from the experience of acting (across diverse genres) itself," said Kim.

Kim is slated to appear in the new romantic comedy series "Can This Love Be Translated?" out next year, and is considering a lead role in the mystery series "Temptation."