The interesting thing about "Itchy and Scratchy" is that it operates as both a satire of mindless violence aimed towards children, as well as a truly righteous example of mindless violence aimed towards children. Real children may not get it on both levels, but I’m a big kid that understands subtext. While this may seem contradictory or hypocritical, there is an important distinction to be had. If I were to make the argument that Tom and Jerry is immoral, I would point out that the cartoon is aimed at children and presented as innocuous and socially acceptable. However, "Itchy and Scratchy" pushes the violence into absurdly grotesque heights, to where there is no longer the indirect assumption that what is being represented is socially acceptable. A young boy might try to copy Tom and Jerry by hitting his brother in the crotch with a ball pean hammer, but he is not likely to poke out his brother’s eyes and replace them with cherry bombs (that would be pretty funny if he did though). You could make a similar argument about horror films. Vile ideas are best distributed to the masses as indirectly acceptable virtues held by characters they sympathize with and hold in high regard (most sitcoms might be good examples). However, (some) horror films push the envelope by presenting violence as thoroughly unappealing, and certainly not as virtuous ideas that your mother would find peachy keen.
At its heart, I Saw the Devil is sort of "Itchy and Scratchy" aimed at the horror movie crowd, where the absurd cartoonish violence is replaced with absolute brutality. Where as Itchy the mouse repeatedly murders Scratchy the cat for no discernible reason except that he’s a sadistic ass clown, I Saw the Devil attempts to reverse this dynamic. A serial killer (Choi Min-Sik from Oldboy, who’s pretty amazing here) murders a beautiful young girl who’s fiancee happens to be a secret service agent. He promises to get revenge, vigilante style, armed with a seemingly justifiable motive.
Our agent hero determines the identity of the killer fairly early on in the film (maybe 30 or 40 minutes into a movie 140 minutes long), and so begins a series of Itchy and Scratchy encounters, where our hero beats the shit out of the killer (torturing him if need be, including some achilles tendon violence that is damn hard to watch), but lets him go so he can catch him again and repeat the process. After all, it wouldn’t be nearly as much fun for Itchy if he just killed Scratchy once. I know cats are supposed to have nine lives, but I think if you blow a cat’s head off with a bazooka at point blank range, that should be good enough.
A major problem with this odd approach to justice is that the killer keeps on brutally murdering women in between getting his ass handed to him. The hero’s dead girlfriend seemed like a really sweet girl, and hardly like someone who would’ve wanted the spiral of grotesque violence to carry on in her name. With the moral justification quickly lost, these violent encounters between the two men builds as some sort of sadomasochistic relationship. The killer would probably prefer this kind of brutal interaction, coupled with the freedom to murder women as he pleases, to simply being stuck in a cell somewhere. So, it’s not like our hero is one of those vigilantes that seek justice that the “system” can’t or won’t provide.
While we’re supposed to sympathise with the hero as he combats a slimy serial killer, I can’t help but lose sympathy for a hero that seems truly selfish, letting women die and defying justice just to repeatedly experience a kind of violent catharsis. Not very heroic if you ask me. I guess the lesson here is that violence is really bad, whether you’re a woman hating piece-of-shit serial killer or a hero using violence to punish the wicked. Of course, I'm referring to real violence. Fake violence can be pretty rad, except when it drags out to 2 1/2 hours. However, it's perfect for bite sized children's programming, as long as these kids realize that what they are laughing at is truly horrifying in the real world.