Mercy for None: Is the So Ji-sub starring Netflix series worth watching?

The seven-episode noir-action series Mercy For None premiered on Netflix on June 6, 2025. Set in a grim and ruthless underbelly of organized crime, the narrative revolves around Nam Gi-jun (played by So Ji-sub), an ex-gang lieutenant who once severed his Achilles tendon to withdraw from syndicate operations.

Over a decade later, Gi-jun is pulled back into the crime circuit following the suspicious passing of his younger sibling, Nam Gi-seok (Lee Jun-hyuk), who was a top-ranking member of a rival crew.

Determined to uncover the motive behind the death, Gi-jun re-enters a violent landscape controlled by two dominant crime empires: one under Lee Ju-woon (Heo Jun-ho) and the other commanded by Koo Bong-san (Ahn Kil-kang), who is grooming his impulsive heir, Koo Jun-mo.

Ju-woon once treated Gi-seok as a protégé, but now heads one of the city’s largest mobs. In contrast, Bong-san manages the opposing syndicate and positions his son as successor.

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Who killed Nam Gi-seok in Mercy For None?

In the opening episode, tensions spike after Jun-mo humiliates Gi-seok in public. Not long after, Gi-seok is fatally attacked. Though initial suspicion circles Jun-mo, it’s later revealed that a mixed-heritage assassin named Kaneyama executed the hit.

Kaneyama acted under the orders of Lee Geum-son (Choo Young-woo), Ju-woon’s calculated son, who leads a double identity as both prosecutor and covert strategist. Supporting him is Cha Yeong-do (Cha Seung-won), a crooked authority figure who’s manipulated both factions for years, sowing chaos for personal gain.

Geum-son proceeds to eliminate his father and enforces a forced merger between the gangs. Believing himself victorious, his crimes are soon broadcast, stripping him of authority and status.

The concluding episode leads to a violent clash. Gi-jun confronts Geum-son, who tries to take his own life. Gi-jun stops him, not to save, but to ensure he feels the downfall. Geum-son dies seated on the chair he schemed to possess, marking the end of his aspirations.

Flashbacks reveal Gi-jun’s past as a core figure in the Bongsan Gang. He played a vital role in expanding their dominance, but chose to exit for his brother’s safety by cutting his own Achilles tendon. Post-retirement, he lived quietly, delivering beverages to businesses tied to the gang.

Gi-seok, meanwhile, rose to second-in-command within Ju-woon’s ranks before his abrupt death. This tragedy prompts Gi-jun’s re-entry into the violent world he abandoned 11 years earlier.

Mercy For None goes further, vindication, it delves into deception and dominance. Coupled with moody visuals and fierce brawls, the series becomes unmissable.

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Mercy For None stands out with silent rage, brutal fights, and gripping storytelling

In Mercy For None, So Ji-sub portrays Nam Gi-jun, a rugged and worn-out lead shaped by personal tragedy. The actor is best known for Doctor Lawyer, Oh My Venus, I'm Sorry, I Love You, My Secret Terrius, and One Sunny Day.

The South Korean artist's part in Mercy for None contrasts with previous portrayals. In this role, his character speaks little, relying on physical expression over dialogue.

Ji-sub conveys sorrow through minimal reactions, as his character pushes through hurdles and confrontations with quiet intensity. His fight scenes are well-coordinated, and his movements feel sharp and realistic.

The series avoids firearms, sticking to fistfights and tight close-ups, keeping the action grounded and personal. The core plot follows Gi-jun, who sets out to track down the people behind his younger brother’s death.

To him, his brother was the only person who mattered. Now, with no attachments left, Gi-jun moves forward without hesitation or fear of death. The narrative doesn’t explore emotional depth much. Gi-jun stays mostly quiet, always appearing distant or grim.

Other key characters also revolve around straightforward goals like vengeance or power. Among female characters, the only major speaking role belongs to a police officer, played by Lee Sang-hee.

As the show progresses, the early promise fades a bit. The plot shifts into repetitive betrayal arcs. The action scenes also begin to feel familiar rather than fresh.

The show wraps in just seven episodes. However, its format leans toward something that might’ve worked better as a compact movie rather than a stretched series.

Nevertheless, the personas in this series are multi-dimensional, with ever-changing allegiances and fierce conflicts. So, for fans of raw underworld sagas with a shadowy edge, Mercy For None hits all the marks.

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Mercy For None is now streaming on Netflix.