You know that feeling when you're watching a movie and the chemistry just... clicks? It’s rare. Usually, you get one standout performance and a couple of supporting actors just trying to keep up. But with Lee Won-tae’s 2019 neo-noir thriller, something weird happened. The The Gangster, The Cop, The Devil cast didn't just play their parts; they created this bizarre, high-tension equilibrium that honestly carries the whole film.
It’s a simple hook. A massive, terrifying mob boss gets stabbed by a random serial killer. He survives, which is bad news for the killer. He then has to team up with a loose-cannon cop to find the guy. If the cop catches him, he goes to jail. If the gangster catches him, he's dead.
Simple, right? But it only works because of the three men at the center.
Ma Dong-seok Is Not Just "The Muscle"
Let’s talk about Don Lee. If you haven't seen Ma Dong-seok (his Korean name) in anything else, you might think he’s just another big guy. You’d be wrong. In this film, he plays Jang Dong-su, the boss of the Zeus Gang.
He’s terrifying.
There is a scene early on where he's using a punching bag. You think it's a normal workout until you realize there is a living human being stuffed inside that bag. It’s a brutal introduction. But Ma Dong-seok brings this weird, quiet charisma to the role. He’s not screaming. He’s not acting like a cartoon villain. He’s a businessman who happens to be able to crush a skull with his bare hands.
What's fascinating about his performance here, compared to his role in Train to Busan or the Roundup series (The Outlaws), is the darkness. Usually, he’s the lovable tough guy. Here, he is a predatory animal. When he's forced to sit in a car with a police officer, the sheer physical presence he occupies makes the frame feel small. You're constantly waiting for him to snap.
Honestly, Ma Dong-seok is the reason Sylvester Stallone’s Balboa Productions jumped at the chance to remake this for American audiences. He’s a once-in-a-generation action star. He has this "heavy" screen presence that you just can't teach.
Kim Mu-yeol and the "Bad Cop" Archetype
Then you have Kim Mu-yeol. He plays Jung Tae-seok, the cop.
💡 You might also like: Is Steven Weber Leaving Chicago Med? What Really Happened With Dean Archer
In a lesser movie, this character would be the "good guy." Not here. Jung is arrogant, violent, and incredibly frustrated. He’s the only one who realizes a serial killer is on the loose, but his bosses think he’s just obsessed.
Kim Mu-yeol had to gain about 15 kilograms of muscle for this role just to look like he could stand in the same room as Ma Dong-seok without getting snapped in half. It worked. He plays the character with this twitchy, nervous energy. He’s like a dog on a leash that’s about to break.
The dynamic between the cop and the gangster is where the movie breathes. It’s not a "buddy cop" vibe. It’s two people who genuinely despise each other but realize they are both the "alpha" in their respective worlds. They trade barbs, they trade punches, and eventually, they trade information. Kim Mu-yeol holds his own against Ma’s massive shadow, which is a testament to how good of an actor he really is. He doesn't try to out-muscle Don Lee; he out-intensifies him.
Kim Sung-kyu: The Devil in the Shadows
If you’ve seen the Netflix series Kingdom, you know Kim Sung-kyu. He played the mysterious sharpshooter. In the The Gangster, The Cop, The Devil cast, he is the "Devil"—Kang Kyung-ho.
He is skinny. He looks fragile. And that makes him ten times scarier.
While the other two leads represent power and authority (one legal, one illegal), Kim Sung-kyu represents chaos. He kills for no reason. No motive. No pattern. He just likes it. The way he smiles—or rather, the way he doesn't smile—is haunting.
There’s a specific stillness to his performance. While the cop is yelling and the gangster is hitting things, the killer is just... there. Waiting. Kim reportedly lost a lot of weight to look more "skeletal" and predatory. It paid off. When the three of them finally converge, it feels like a collision of three different styles of violence.
Why the Chemistry Works
You see, most action movies fail because the villain is weak. Or the hero is too perfect.
📖 Related: Is Heroes and Villains Legit? What You Need to Know Before Buying
This movie avoids both.
The script is tight, but it’s the physical performances that sell the stakes. You have the immovable object (The Gangster), the unstoppable force (The Cop), and the wild card (The Devil).
- Ma Dong-seok provides the gravity.
- Kim Mu-yeol provides the frantic pace.
- Kim Sung-kyu provides the cold shivers.
It’s a masterclass in casting. If you swapped any of these guys out, the movie would probably fall apart into a generic "cat and mouse" thriller.
The Supporting Cast You Might Miss
While the "Big Three" get all the glory, the ensemble around them anchors the world.
Heo Dong-won plays Choi Moon-sik, the gangster’s right-hand man. He’s been in a ton of Ma Dong-seok’s movies, and they have a natural shorthand that makes the gang hierarchy feel real. Then you have Yoo Seung-mok as the police chief. He’s the classic "angry boss" who won't listen, but he plays it with a level of realism that makes you understand why he's so dismissive of the serial killer theory.
These smaller roles matter because they ground the movie. They remind you that while these three protagonists are larger-than-life figures, they exist in a world with rules, bureaucracy, and consequences.
Behind the Scenes Nuance
Director Lee Won-tae knew what he was doing when he assembled this group. He didn't just want famous faces; he wanted specific "vibes."
He’s mentioned in interviews that the hardest part was finding the "Devil." He needed someone who didn't look like a typical movie villain. He wanted someone who looked like a guy you’d pass on the street and never notice. That’s what makes Kim Sung-kyu’s performance so chilling. The banality of evil.
👉 See also: Jack Blocker American Idol Journey: What Most People Get Wrong
And then there's the physical training. The fight choreography wasn't just "cool moves." It was character-driven. The gangster fights with heavy, crushing blows. The cop fights like a brawler. The killer fights with a knife—quick, surgical, and mean.
What This Film Says About the Genre
The The Gangster, The Cop, The Devil cast highlights a shift in South Korean cinema. We’re moving away from the purely melodramatic or the overly stylized "hero" stories.
This film is grimy. It’s cynical. It suggests that sometimes, to catch a monster, you have to let a different kind of monster help you.
It also proved that Ma Dong-seok is a global commodity. After this film screened at Cannes, it was clear he was ready for the MCU (which led to Eternals). But honestly? He’s much better in roles like this. He’s better when he’s allowed to be a little bit "bad."
How to Appreciate the Cast Even More
If you want to see how versatile these actors are, you should definitely check out their other work. It puts their performances here in a whole new light.
- Watch Kim Sung-kyu in Kingdom: You’ll see him as a hero (mostly), and the contrast with his role as the "Devil" is shocking. It shows his range.
- Check out Ma Dong-seok in Derailed: Before he was the "King of Punching," he played a very different kind of character. It’s a gritty indie film that shows his dramatic acting chops.
- Look for Kim Mu-yeol in Forgotten: This is a psychological thriller on Netflix. His performance there is mind-bending and proves he’s one of the best leading men in Korea right now.
The best way to experience this cast is to pay attention to the silence. Don't just watch the fight scenes. Watch the way they look at each other in the scenes where nobody is talking. The tension is thick enough to cut with a knife.
If you're looking for a deep dive into the technical side of the production, look for the "making of" featurettes usually found on the Blu-ray releases or specialized Korean film forums. They go into the stunt coordination and how Ma Dong-seok actually helped choreograph some of the more brutal takedowns.
The real takeaway here is that great cinema isn't just about a great script. It's about finding the right people to inhabit that script. The The Gangster, The Cop, The Devil cast didn't just inhabit it—they owned it.
To truly understand why this film works, your next step should be to watch the original Korean version before the Hollywood remake eventually hits theaters. Pay close attention to the final scene in the prison. The look on Ma Dong-seok’s face tells you everything you need to know about the character’s soul without a single word being spoken. That is the power of elite casting.