The Merciless

Cinematography

• 
  Lee Hyung Bin
• 
  Jo Hyeong Rae

Composer

• 
  Kim Hong Jib
• 
  Park Yong Gi

Costume Designer

• 
  Jo Hee Ran

Editor

• 
  Kim Jae Bum
• 
  Kim Sang Bum

Producer

• 
  Jung Tae Sung

Screenwriter

• 
  Kim Min Soo

Screenwriter & Director

• 
  Byun Sung Hyun

Visual Effects

• 
  Choi Jae Cheon
• 
  Lee Dong Hun
• 
  Lee Jeong Hyeon
• 
  Lee Jong Mu
• 
  Lee Jeon Hyoung

Main Role

• 
  Sul Kyung Gu

  Han Jae Ho

  Main Role
• 
  Yim Si Wan

  Cho Hyeon Su

  Main Role

Support Role

• 
  Kim Hee Won

  Ko Byeong Gap [Byeong Cheol's nephew]

  Support Role
• 
  Jeon Hye Jin

  Cheon In Suk [Police captain]

  Support Role
• 
  Lee Kyung Young

  Ko Byeong Cheol / Chairman Ko [Ocean Trading]

  Support Role
• 
  Jang In Sub

  Min Cheol [Police officer]

  Support Role
• 
  Moon Ji Yoon

  Yeong Geun [Jae Ho's trusted aide]

  Support Role
• 
  Park Soo Young

  Pastor Jang [Prisoner]

  Support Role
• 
  Choi Byung Mo

  Captain Choi

  Support Role
• 
  Nam Gi Ae

  [Hyeon Su's mother]

  Support Role
• 
  Jin Seon Kyu

  [Prison Security Section chief]

  Support Role
• 
  Kim Ik Tae

  [Busan police commissioner]

  Support Role
• 
  Lee Ji Hoon

  Prosecutor O

  Support Role
• 
  Go Bong Goo

  Ho Yul

  Support Role
• 
  Hong In

  Bang Gae

  Support Role
• 
  Choi Jun Young

  Yong Chan

  Support Role
• 
  Kim Ji Hoon

  Jeong Sik [Seong Han's right hand man]

  Support Role

Guest Role

• 
  Kim Sung Oh

  Jung Seung Pil [Undercover agent]

  Guest Role
• 
  Huh Joon Ho

  Kim Seong Han

  Guest Role
• 
  Shin So Yool

  [Ocean Trading advertising beauty #1]

  Guest Role
• 
  Kim Bo Mi

  [Ocean Trading advertising beauty #2]

  Guest Role
• 
  Lee Mi So

  [Ocean Trading advertising beauty #3]

  Guest Role
• 
  Jeon Kwon Ha

  [Captain Choi's gang]

  Guest Role

Bit part

• 
  Kim Sung Gon

  Yeong Chi Pum [Prison guard]

  Bit part
• 
  Jason Scott Nelson

  Vlad [Gegard gang member]

  Bit part
• 
  Lee Tae Geom

  [Byeong Gap's subordinate #1]

  Bit part
• 
  Kim Se Jun

  [Byeong Gap's subordinate #2]

  Bit part
• 
  Kwak Jin Seok

  [Jae Ho's gang #1]

  Bit part
• 
  Na Seok Min

  [Seong Han's gang member]

  Bit part
• 
  Ju Ye Eun

  [Café selfie woman]

  Bit part
• 
  Lee Dong Yong

  [Cold warehouse manager]

  Bit part
• 
  Jo Young Ji

  [Emergency room nurse]

  Bit part
• 
  Lee Gyu Ho

  [Jjakjjaki inmate #1]

  Bit part
• 
  Won Gun Su

  [Jjakjjaki inmate]

  Bit part
• 
  Shin Seong Hoon

  [Police executive]

  Bit part
• 
  Seo Yoon Ha

  [Conference room secretary]

  Bit part
• 
  Choi Young Min

  [Beach gang member]

  Bit part
• 
  Im Yong Soon

  [Police officer]

  Bit part
• 
  Kim Bong Jo

  [Security and prison guard]

  Bit part
• 
  Kim Won Shik

  [Cigarette inmate]

  Bit part
• 
  Park Jun Hyuk

  [CRPT]

  Bit part
• 
  Park Ji Ho

  [CRPT]

  Bit part
• 
  Ahn Sung Bong

  [CRPT]

  Bit part
• 
  Jung Ki Wook

  [CRPT]

  Bit part
• 
  Kang Min Gu

  [Rehab Jae Ho's gang]

  Bit part
• 
  Kim Dae Geun

  [Rehab Jae Ho's gang]

  Bit part
• 
  Lee Jung Ho

  [Rehab Jae Ho's gang]

  Bit part
• 
  Kim Hyun Chang

  [Rehab Jae Ho's gang]

  Bit part
• 
  Kang Min Tae

  [Captain Choi's gang]

  Bit part
• 
  Ryu Dae Shik

  [Captain Choi's gang]

  Bit part
• 
  Ryu Ki San

  [VIP room organization member]

  Bit part
• 
  Yeom Jin Kwon

  [VIP room organization member]

  Bit part
• 
  Lee Dong Young

  [VIP room organization member]

  Bit part
• 
  Ko Dong Hyoung

  [Police commando]

  Bit part
• 
  Kim Hee

  [Police commando]

  Bit part
• 
  Hong Joon Woo

  [Police commando]

  Bit part
• 
  Choi Sun Woong

  [Police commando]

  Bit part
• 
  Hwang Yun Sung

  [Police commando]

  Bit part
• 
  Choi Hyoung Uk

  [Police commando]

  Bit part
• 
  Kim Sung Joon

  [Ocean Trading executive]

  Bit part
• 
  Kim Tae In

  [Ocean Trading organization member]

  Bit part
• 
  Joseph Kim

  [Ocean Trading organization member]

  Bit part
• 
  Shin Jae Min

  [Ocean Trading organization member]

  Bit part
• 
  Lee Jung Woo

  [Ocean Trading organization member]

  Bit part
• 
  Choi Hyun Jong

  [Ocean Trading organization member]

  Bit part
• 
  Yoo Young Bok

  [Ocean Trading executive]

  Bit part
• 
  Yoo Sun Ho

  [Ocean Trading organization member]

  Bit part
• 
  Jo Ki Tae

  [Kim Sung Han's gang member]

  Bit part
• 
  Baek Chun Ki

  Dok Hang Sun [Incheon street detective]

  Bit part
• 
  Lee Chang Won

  [Young man on Incheon streets]

  Bit part
• 
  Kim Sung Gang

  [New inmate]

  Bit part
• 
  Lee Tae Hwan

  [New inmate]

  Bit part
• 
  Andreas Fronk

  [Russian mafia]

  Bit part
• 
  Park Gwang Jae

  [2m big guy]

  Bit part
• 
  Carson Allen

  [Russian woman]

  Bit part
• 
  Kim Ki Ho

  [Official gang #1]

  Bit part
• 
  Seo Tae Sung

  [Official Gang #2]

  Bit part
• 
  Park Young Woong

  [Detective #1]

  Bit part
• 
  Lee Seung Chan

  [Detective #2]

  Bit part
• 
  Moon Jin Sik

  [Detective #3]

  Bit part
• 
  Yoon Young Kyun

  [Jae Ho's gang #2]

  Bit part
• 
  Lee Si Hoon

  [Jae Ho's gang #3]

  Bit part
• 
  Yang Hyun Min

  [Investigator]

  Bit part
• 
  Kim Tae Jeong

  [Russian club girl]

  Bit part

Unknown

• 
  Kang Dong Soo Unknown