This review may contain spoilers. I can handle the truth.
Matt Lavender’s review published on Letterboxd:
This review may contain spoilers.
I have a theory about all this madness
I can't remember the characters' names and I'm a lazy shitheap so it's Good Guy and Bad Guy (although that's fucking questionable).
So the general idea is that Good Guy (the South Korean Ryan Gosling) plays a big cat and mouse game with Bad Guy (awesome dude from Old Boy, South Korean Jack Nicholson maybe), catching and violently attacking him before releasing him so Bad Guy ends up causing more carnage.
There's the whole Pavlovian Conditioning thing too, Good Guy brutally attacks Bad Guy only to let him go. Bad Guy just fucks up more people because he hasn't been conditioned at all (he's a fucking lunatic). Good Guy shows up again to attack him and it goes on and on until the end.
I have this idea right that the Good Guy is a twisted fuck in his own way. When he first finds the Bad Guy about to rape that kid he nearly smashes his head in with a rock but doesn't. So either he's deciding to let him go only to catch up with him later (cat and mouse) oooorrr maybe he's not at the point where he can bring himself to kill Bad Guy outright.
So Bad Guy did violently murder Good Guy's wife and you'd reckon that'd be enough to set the whole cat and mouse thing in action but maybe Good Guy is so fucked in the head that even after this bad dude killed his wife he can't bring himself to kill him.
Maybe Good Guy needs Bad Guy to kill/rape like 20 more people in order to finally bring himself to kill him, hence the attacking and letting him go stuff.
I haven't got much to back this shit up but in the opening scene Good Guy is at work on his wife's birthday and he always seems a bit cold/distant, maybe they weren't that close, maybe he needs Bad Guy to go on his rampage to justify murdering him. Maybe he's always been a bit off a lunatic himself and his wife's murder sort of brought it out in him.
Fuck knows if that makes sense (I don't even agree with myself) but anyway I Saw The Devil is an OTT masterful revenge movie.
4.5 stars because it's so re-watchable but a bit long and rambling here and there.