So here's the fucked up thing about I Saw The Devil.
It's a film about how ultimately dehumanizing and unsatisfying vengeance can be. The movie is a revenge story through-and-through, and revenge stories exist to empower the powerless through fiction. Bad things happen in life and our sense of order demands that someone be punished for it. It's a nice power fantasy and most revenge films feature an average man empowered by rage.
Kyung-chul, the serial killer who murdered Soo-hyun's pregnant fiance, is about as evil as they come. He spends the entire movie kidnapping, raping, and murdering women. His only friend is a cannibal who invades homes and carves up the inhabitants for supper. They're both shabby and unattractive men, though Kyung-chul approaches his work with a steely eyed, world-weary assertiveness that's undeniably compelling to watch. They're both evil men but they're not quite devils. There's something petty and pathetic about them that puts me in the mind of something I read this week: "Most things that seem satanic or malevolent are really just wretchedness and frailty that’ve been allowed to put on muscle."
Neither murderers have a chance against Soo-hyun. Soo-hyun is the perfect human agent of vengeance. Young, handsome, highly-trained, and brutal, Soo-hyun is basically a Korean Jason Bourne. After his fiancee's body is found at the bottom of a river (in one of the most chilling search-team scenes I've ever seen), Soo-hyun steals some spy gadgets from his office, takes a two-week vacation, and goes hunting. With the help of his fiancee's father, a former police commissioner, he quickly tracks down his fiancee's killer. The rest of the game is a brutal game of cat and mouse between the serial killer and the super agent. Soo-hyun refuses to turn his prey over to the police, preferring to prolong his quarry's torment, and Kyung-chul descends into depravity when faced by an opponent who outclasses him in every way.
This movie had been sitting in my Netflix queue for awhile because I felt like I could figure out how it would end from the synopsis: Soo-hyun would descend into Kyung-chul's level until the difference between the two men was almost nil. While Soo-hyun's revenge does eventually barrel over innocent people, the story is never that trite or obvious. No satisfying revenge can really be taken against Kyung-chul anyway. Soo-hyun can cause horrific physical pain to Kyung-chul (and some of his attacks run close to torture porn) but the effect is similar to Batman beating up the Joker in the interrogation room: a guy as crazy as Kyung-chul is eventually going to disconnect from what's happening to him and all you're left with is cutting flesh. Even torturing Kyung-chul inside his murder room fails to stir any empathy for his victims. Instead he goads Soo-hyun to kill him and treats Soo-hyun like he's wasting Kyung-chul's time.
So the film's title doesn't refer to Kyung-chul. Kyung-chul is essentially a selfish, ignorant creature of the id. The devil in the title is the realization that you can burn your entire life down to gain the object of your obsession and have it mean absolutely nothing. The movie ends without closure and with a sense of loss that's almost crippling. While researching this blog post, I came across the perfect one-sentence review for the film: "There is all the violent mayhem, for certain, but the thing that sets I Saw the Devil apart is its undercurrent of real emotion and how unrelentingly sad it can be."