Kyung-chul is a dangerous psychopath who kills for pleasure. Soo-hyeon, a top-secret agent, decides to track down the murderer himself. He promises himself that he will do everything in his power to take vengeance against the killer, even if it means that he must become a monster himself.
Unfortunately the movie I Saw the Devil is not yet available on HBO Max.
| Visual Effects | Kang Jong-ik | VFX Supervisor |
| Visual Effects | Jung Do-ahn | Special Effects Supervisor |
| Art | Jeon Sung-ho | Set Decoration |
| Crew | Han Jeong-uk | Stunts |
| Sound | Kim Kyung-tae | Production Sound Mixer |
| Editing | Nam Na-young | Editor |
| Writing | Park Hoon-jung | Screenplay |
| Camera | Lee Mo-gae | Director of Photography |
| Sound | Mowg | Original Music Composer |
| Lighting | Oh Seung-chul | Gaffer |
| Crew | Lee Hee Kyung | Special Effects |
| Writing | Lee Yoon-ho | Storyboard |
| Editing | Kim Hyung-seok | Digital Colorist |
| Camera | Lee Jong-woo | Camera Operator |
| Visual Effects | Yang Il-seok | VFX Supervisor |
| Visual Effects | Son Seung-hyeon | VFX Supervisor |
| Camera | Lee Jae-hyeok | Still Photographer |
| Directing | Kim Jee-woon | Director |
| Writing | Kim Jee-woon | Screenplay |
| Costume & Make-Up | Lee Hee-eun | Makeup Effects Designer |
| Art | Jo Hwa-seong | Production Design |
| Sound | Park Yong-gi | Sound Re-Recording Mixer |
| Sound | Choi Tae-young | Supervising Sound Editor |
| Sound | Romain Bigorgne | Sound Effects Editor |
| Sound | Dong-Han Kim | Sound Effects Editor |
| Costume & Make-Up | Kwak Tae-yong | Makeup Effects Designer |
| Sound | Choi Tae-young | Sound Re-Recording Mixer |
| Crew | Jung Doo-hong | Fight Choreographer |
| Camera | Kim Byung-seo | Camera Operator |
| Sound | Gang Hye-yeong | Sound Editor |
| Directing | Seok Min-u | Assistant Director |
| Art | Son Min-jeong | Conceptual Design |
| Costume & Make-Up | Kim Hyun-jung | Makeup & Hair |
| Costume & Make-Up | Kwon Yoo-jin | Costume Design |
| Editing | Kim Mi-young | Editor |
| Art | Kim Byung-han | Conceptual Design |
| Production | Cho Seong-won | Co-Executive Producer |
| Production | Kim Jae-young | Producer |
| Production | Kim Jung-hwa | Producer |
| Production | Kim Hyun-woo | Executive Producer |
| Production | Nam Seong-ho | Line Producer |
| Art | Kim Cho-hea | Set Decoration |
| Crew | Heo Myeong-haeng | Fight Choreographer |
| Visual Effects | Jung Sung-jin | Visual Effects Supervisor |
| Costume & Make-Up | Pi Dae-seong | Special Effects Makeup Artist |
