Mantis

Watch Mantis (2025) in high definition (HD, 720p and 1080p) on WatchBolly, completely free and without registration. This South Korean action thriller directed by Lee Tae-sung in his feature debut serves as a spin-off to the 2023 Netflix hit Kill Boksoon, expanding that film's assassin universe with style and intensity. Yim Si-wan stars as Han-ul, code-named Mantis, an elite killer who returns from vacation to find the contract killing industry in chaos following the downfall of MK Enterprise. As he attempts to establish his own company, he encounters his former training partner Jae-yi (Park Gyu-young) and legendary retired mentor Dok-go (Jo Woo-jin), discovering that loyalty means nothing in a world where everyone competes to become the number one assassin. Running 111 minutes, this sleek thriller delivers knife-focused action choreography and complex relationship dynamics.

Expanding the Kill Boksoon Universe

Mantis originated from a brief mention in Kill Boksoon, where the titular character was referenced as being "on vacation." That throwaway line has now expanded into a full feature that explores a different corner of the assassin underworld established in the 2023 film. Writer-director Lee Tae-sung collaborated with Kill Boksoon creator Byun Sung-hyun to maintain continuity while creating a distinct tonal identity. Where the original film combined action with psychological horror elements, Mantis pursues a more straightforward action-thriller approach with romantic undertones.

The premise finds Han-ul returning to discover that Gil Boksoon's actions have destabilized the entire contract killing industry. MK Enterprise's collapse has created a power vacuum where multiple factions compete for dominance, forcing Mantis to navigate shifting alliances and emerging threats. This world-building expands the mythology established in the first film while telling a complete story accessible to viewers unfamiliar with Kill Boksoon. Familiar characters and locations connect the productions while new elements distinguish Mantis as its own entity.

Yim Si-wan Transforms as an Action Star

Known primarily for softer roles in dramas like Summer Strike, Yim Si-wan makes a dramatic transformation as the lethal Mantis. His preparation included extensive martial arts training to credibly perform the film's knife-centric combat sequences, developing the physicality required for convincing action performance. Beyond the physical demands, Yim brings emotional complexity to a character navigating professional chaos while harboring deep feelings for someone who doesn't reciprocate his affection.

The romantic tension between Mantis and Jae-yi provides emotional stakes beyond the action, as Park Gyu-young portrays a fierce competitor whose career ambitions leave no room for sentiment. Their shared history as training partners adds depth to their current rivalry, with each interaction carrying subtext about paths taken and feelings suppressed. Jo Woo-jin as the mentor-turned-rival Dok-go completes a triangle of relationships that gives the action personal meaning beyond mere survival.

Blade Combat and Stylish Choreography

Mantis distinguishes itself through emphasis on blade combat rather than gunplay, creating action sequences that feel fresh within the assassin genre. The choreography showcases various knife-fighting techniques in extended sequences that demonstrate clear spatial geography and impressive physical performance from the leads. Director Lee Tae-sung proves capable of staging and shooting action with clarity and style, delivering set pieces that satisfy genre expectations while establishing his own voice.

The film's later acts escalate the action intensity, delivering the satisfying confrontations that the slow-burning setup promises. While some viewers felt the early pacing deliberate, those who stayed invested found payoffs in climactic sequences that showcase what the cast and crew can achieve. The production design and cinematography maintain the slick aesthetic established in Kill Boksoon while giving Mantis visual identity through its specific location choices and color palette.

Complex Loyalties in a Ruthless World

Beyond its action elements, Mantis explores themes of loyalty, ambition, and the impossibility of human connection within a world defined by betrayal. Mantis's crush on Jae-yi represents a longing for normalcy that his profession renders impossible, while her single-minded focus on advancement shows how the industry shapes those within it. Dok-go's return from retirement demonstrates that no one truly escapes this world, that past relationships carry forward in complicated ways.

The film doesn't shy away from moral ambiguity, presenting characters who are professional killers without attempting to justify or condemn their choices. This approach allows viewers to engage with the drama on its own terms, investing in character dynamics without requiring ethical resolution. Whether the assassin universe continues expanding with additional spin-offs remains to be seen, but Mantis successfully demonstrates that this world contains stories worth telling beyond the original film.

Stream Now on WatchBolly

Experience Mantis in HD quality on WatchBolly across all your devices. This stylish Korean action thriller delivers impressive knife choreography, complex character relationships, and expansion of the Kill Boksoon universe that fans have anticipated. Whether you're drawn by Yim Si-wan's action star transformation, the slick thriller elements, or the romantic tension amid professional rivalry, Mantis offers satisfying genre entertainment. Stream free without registration and discover why this spin-off has earned its place in Korean action cinema.