The Gangster, the Cop, the Devil - Characters & Cast

His primary motivation is restoring his reputation in the criminal underworld and exacting personal revenge on the man who dared to attack him and made him look weak.

Jang Dong-soo begins as a feared, untouchable crime boss. After surviving the attack, his arc becomes one of vulnerability and obsession. He is forced to humble himself by partnering with a cop he detests. His journey is not about redemption, but about reclaiming his alpha status through vengeance. By the end, he manipulates the legal system itself to ensure his personal, brutal form of justice is served.

He is driven by a mix of genuine desire to stop the killer and a powerful ambition for career advancement and recognition. He is determined to prove his superiors wrong and solve the case no one else believes in.

Jung Tae-seok starts as an arrogant, rule-bending detective frustrated by a corrupt system. His arc is a descent into deeper moral compromise. By aligning with a gangster, he blurs the line between cop and criminal. While he succeeds in his goal of capturing the killer and earning a promotion, he does so by making a deal with the devil, ultimately enabling the gangster's final act of revenge.

The film presents his motivation as non-existent beyond the sadistic pleasure of killing. He is a representation of random, unpredictable violence, which makes him a terrifying and enigmatic antagonist.

Kang Kyung-ho has no discernible arc; he is a static force of pure, motiveless evil. He begins and ends as a sadistic killer who enjoys the chaos he creates. His character's only shift is in the final scene, where his signature unnerving smile finally vanishes when he realizes he is trapped with the one victim who survived and is bent on revenge.