On any number of levels, "Devil" is troublesome at best, offensive at worst.
What are people saying?
What are critics saying?
Eventually, Soo-hyun's relentless pursuit-and-release approach outlives the director's skill and the premise starts to feel redundant.
Ultimately, the returns of the film's premise can't justify a nearly two-and-a-half-hour squirm. The savagery is honest, raw and hardly entertainment.
Entertainment Weekly by Lisa Schwarzbaum
Somewhere in all the blood (sickening realism is a selling point), a question is posed: When does the one fighting a monster become a monster himself?
Village Voice by Michael Atkinson
Never good with nuance, Kim is a beast with disarming imagery but has few resonating ideas, leaving the domino-tumble of brutality to become its own tiresome spectacle.
Boxoffice Magazine by Pam Grady
Plenty of people die in I Saw the Devil, but it is that first attack on Ju-yeon in the movie's opening minutes that reverberates through the epic 141-minute running time.
Repugnant content, grislier than the ugliest torture porn, ought to have made the film unwatchable, but it doesn't, simply because Kim's picture is so beautifully filmed, carefully structured and viscerally engaging.
A mesmerizing study of the nature of evil itself.
You won't soon forget it -- if you have the guts to see it.