Even for veteran performer Song Se-byeok, 42, who debuted in 1988 as a stage actor, understanding the reckless character of Kyung-pil in the upcoming film “Special Cargo” by Park Dae-min was not easy.

“Special Cargo” is a crime-action film that centers around a professional delivery driver named Eun-ha (Park So-dam). She delivers anything that cannot be delivered legally. One day, Eun-ha receives a mission to deliver a young boy named Seo-won (Jung Hyeon-jun) who is being chased by a criminal group. They are after his key, which opens a safe that holds 30 billion won ($25.12 million). When she decides to save Seo-won, she becomes a target.

Song’s character Kyung-pil is the leader of the crime group, which will do anything for money.

In the new film, the actor pulls off the character so naturally that the audiences would have a hard time believing that he struggled to play the character.

“When I was playing this character, I had bad headaches. I could not sleep well and could not eat properly either. It was also hard to be separated from the character afterward. It never was easy for me, but I think this character was by far the worst,” Song said during an online interview with a group of reporters on Monday.

Song explained that his struggles started from the very beginning.

“I didn’t understand Kyung-pil at first. When I am playing a villain, I try to find a point that I can sympathize with. But I could not find that in my character this time,” Song said.

The actor later discovered that he does not have to always sympathize with the character to play the role.

“Actually, I think I was able to perform it better because I could not sympathize with him,” he said.

Song explained that he just considered Kyung-pil as a straightforward person with one clear goal, which is to get back his money.

“One of his lines emphasizes that the lost money is worth 30 billion won, not 3 million won. It clearly shows that his purpose is money, and he would do anything to get it back,” he said. “I also tried to understand him using my imagination. I thought that there must be a reason why he became this way. It could be the environment in which he was raised.”

Song added that even after resolving his issues about not being able to sympathize with the character easily, it was not easy to play Kyung-pil, which led him to have bad headaches throughout the filming.

The headaches were from the pressure of playing a bad guy, he said,

“The first scene that I performed was Kyung-pil smacking Yeon Woo-jin with a bat. I felt a lot of pressure doing that scene in particular,” he said.

When asked if he wanted to perform a nicer character next time, Song responded enthusiastically.

“Yes, I want to so badly,” he said. “Don’t get me wrong. Playing a villain character was sort of satisfying because I could let out some emotions through it, but I also want to do something different now. Maybe a nicer person next time.”