Yaksha: Ruthless Operations

• Sol Kyung-gu as Ji Kang-in, head of the Shenyang branch of the NIS[5] and nicknamed "Yaksha". Willing to go to any means, including breaking the law, to achieve the branch's missions.
• Park Hae-soo as Han Ji-hoon, a former prosecutor from the Seoul Central District Prosecutors' Office[6] and inspector to the NIS Shenyang Branch. In contrast to Kang-in, he believes justice should be upheld through law. At the end of the film, he returns to the Prosecution Office with a new perspective on justice.
• Hiroyuki Ikeuchi as Ozawa Yoshinobu, a Japanese spy disguised as a former Japanese intelligence officer[7] and lobbyist. He sets up the Black Team for the murder of Moon Byung-uk.

• Yang Dong-geun as Section Chief Hong, an agent of the Black Team later revealed to be a mole working for Director Yeom.
• Lee El as Hee-won, a veteran senior agent of the Black Team.[8]
• Song Jae-rim as Jae-gyu, an agent of the Black Team.
• Park Jin-young as Jeong-dae, the youngest member of the Black Team.[9]

• Jin Kyung as Yeom Jeong-won, Director of the 4th Bureau in charge of NIS foreign intelligence activities.[10] Suspicious of the Black Team's activities, she sends Ji-hoon to Shenyang. Later revealed to be working for Ozawa Yoshinobu and had successfully turned NIS agents into moles. The Black Team ambushes her and hands her over to Ji-hoon at the end of the series.

• Nam Kyung-eup as Moon Byung-uk, head of Room 39 a group part of the North Korean Central Committee involved in maintaining the Kim family's slush funds. He is pursued by various parties who wants the information he holds and for intending to defect to South Korea through the Black Team. He pleads Kang-in to protect his daughter before dying.
• Lee Soo-kyung as Moon Ju-yeon, daughter of Moon Byung-uk who has information that all parties are pursuing.[10] Revealed that her father was deceived to work for the Japanese and wishes to make public a list of double agents managed by Ozawa Yoshinobu. Made a member of the Black Team in the ending credits.

• Jin Seo-yeon as Ryun-hee, an intelligence officer of the North Korean Security Agency which operates a North Korean restaurant in Shenyang.[10] Exchanges intel with the Black Team and in a relationship with Kang-in.
• Kim Jong-man as Hak-cheol

• Kim Seung-hoon as Department Head Hwang of the Seoul Central District Prosecutors' Office.
• Ha Jung-min, Kim Han-joon, and Lee Jin-seung as Prosecutors working in the same team as Han Ji-hoon in the Sangin Group case.
• Choi Won-young as Lee Chan-young, President of Sangin Group. Besides stock manipulation and bribery, it is later revealed that Sangin is also involved in financing payments for Japanese spies.
• Yang Mal-bok as Ji-hoon's mother and owner of a restaurant near Suwon City Hall.
• Ji Yi-soo as Ji-hoon's sister and owner of a restaurant near Suwon City Hall.
• Lee Ji-hoon as the prosecutor who sent Han Ji-hoon to Shenyang.[11]

In the week from April 4 to April 10, Yaksha: Ruthless Operations was at 3rd place in the Global Top 10 weekly list of the most-watched Netflix films (Non-English) with 12.54 million viewing hours.[16][17] It topped the most streamed movie list in the Asian region.[18]

The review aggregator website Rotten Tomatoes reported a 67% approval rating, based on 6 reviews with an average rating of 6/10.[19]

Kim Bo-ram reviewing for Yonhap News wrote that the film is a "pulsating spy thriller set in precarious political landscape in Northeast Asia". Kim praised the performance of actor Sol Kyung-gu, stating that he "well portrays Kang-in", and "his performance creates an unexpected on-screen chemistry with Park Hae-soo". Kim opined that, unlike other spy films, this "action-packed thriller takes a different approach, revolving around a non-professional agent drawn into the dangerous and relentless intelligence operation." She appreciated "its action set-pieces", and stated that "gun shootouts are one of the outstanding parts of the film."[20]

Johnny Loftus of Decider, recommending to stream the film, wrote, "Yaksha: Ruthless Operations brings a heap of trigger-happy spycraft to its tale of secrets and lies and two-faced promises on the way to sorting out some hard-earned justice."[21] Loftus stated that the film "hums with ease through... tightly-edited action sequences" and noted that visually, it "benefits from palette, with neon reds bleeding in from every corner of the frame", showing the "gleaming, teeming Shenyang cityscape."[22]

James Marsh of the South China Morning Post rated the film with 2 out of 5 stars and wrote, "Sluggish, predictable and almost wilfully devoid of thrills, South Korean action drama Yaksha: Ruthless Operations offers none of the unpredictable or mischievous antics teased by its curious title." Marsh concluded "[it] is a blandly functional thriller, executed with workmanlike competence, that woefully lacks any discernible glamour, intelligence or style."[23]