I Saw The Devil - Region 2

Kim Jee-Woon directs this brutally visceral Korean revenge thriller. When his pregnant fiancee becomes the latest victim of maniacal serial killer Kyung-chul (Min-sik Choi), secret agent Dae-hoon (Byung-hun Lee) takes the law into his own hands and sets out on a merciless, bloodthirsty mission to make Kyung-chul's existence a living hell.