Every 18 years, the martial artists' community holds a contest to elect a new leader. Eva Palace's ruler, Sharla Cheung Man, wins the title and is tasked with eliminating the Ten Villains, who live in the Villains' Valley, a sanctuary for criminals who diverted charity funds intended for flood victims in Eastern China. Yin Nam Tin, [Michael Miu Kiu-Wai], the ruler's husband, believes the villains are innocent and tries to stop his wife from carrying out the killings. The couple's clash ends with Yin defeating Eva, but leaving her paralyzed and mute. Eva then welcomes a girl named More as her disciple, training her to disguise as a man in order to groom her as a future successor. Meanwhile, the Ten Villains take Yin's son, Fishy, as their student and plot to mold him into the greatest villain ever to challenge Eva.
Eighteen years pass, and the grown Fishy is sent by the Villains' Valley to participate in the Champion of the Martial World and to locate two former members who stole charity funds. He travels with his surrogate parents Big Mouth Lee and Sissy To, but strays during the journey and is captured by the Black Widow’s palace, where the Empress/Black Widow [Josephine Koo Mei-Wah] is served by male slaves. More rallies her forces and leads an assault on the palace, killing the Black Widow. In the chaos, Fishy helps Kong Yuk Long, one of the palace’s slaves, escape and encounters More, who is struck by his charm and beauty.
At the gathering for the Champion of the Martial World, Fishy, More, and the Kong father and son—Kong Yuk Long and Kong Pi Hawk—advance to the finals, while Monk Blackie [Fung Hak-On] schemes with Yuk-long to use Fishy and More to topple Eva and raise Yuk-long to the top. That night, Big Mouth Lee [Richard Ng Man-Tat] and Sissy To [Deanie Yip Tak-Han] disguise themselves as the Twin Martial Supremes and trap Fishy and More in an underground hole to tempt Fishy into wooing More, hoping to tarnish her reputation and remove her from the competition. More discovers the ruse and resists, while Madam Ti [Anita Yuen Wing-Yee] and her team rush to More’s room, forcing a confrontation that exposes the deception.
In the first round of eliminations, Fishy, More, and the Kong duo reach the finals. Monk Blackie plots with Yuk-long to use Fishy and More to undermine Eva, while the real Twin Supremes are discovered and a skirmish ensues when Pi Hawk’s forces intervene. Fishy arrives to help Big Mouth and Sissy escape, and More also comes to the rescue, only to be captured again by Eva. Yet the Twin Supremes insist that any personal conflicts be resolved after the contest.
The Kongs reveal to Eva More’s genuine affection for Fishy, while poison-laced Mad Wine drains Eva’s energy. As the finals approach, Fishy encounters More in her room, sensing her true feelings but is interrupted by Eva, who scolds More for loving a man and withholds the antidote to the Fatal Luosha Pill until More defeats Fishy the next day.
At the battlefield, Fishy faces More in a staged duel for the next round. When More refuses to deliver a decisive strike, Eva steps in to attack Fishy, but More absorbs the impact and takes another blow herself. Monk Blackie then reveals a deeper truth: Fishy is Eva’s son with Yin Nam Tin. Overcome with remorse, Eva descends into madness as the Mad Wine takes full effect, and the Kongs exploit the moment to eliminate her while Yuk-long finds the antidote to the Fatal Luosha Pill. Fishy and More escape with Big Mouth and Sissy as Yi-hawk is declared Champion of the Martial World after Yuk-long refuses to fight his own father until the Twin Martial Supremes reveal his theft of charity funds from the Black Widow’s account. Yin’s death follows shortly after, and Yuk-long begins studying the Ice Cold Flaming Palm under the Twin Supremes’ tutelage, only to repay their mentorship by crippling their powers and turning their energy against them.
Fishy and More marry in the vigil of Yin’s spirit tablet, a union witnessed by their allies as the Twin Supremes pursue enemies and caution them to settle old scores. The Twins teach Fishy to tap into Yin’s energy to save More from the Fatal Luosha Pill, but Yin dies soon after More is saved. The Twins also impart the Affectionate Couples’ Sword, a technique intended to seal their bond and defeat Yuk-long.
Kong Yuk-long captures other members of the Ten Villains and publicly executes two of them before being challenged by Fishy and More. They sabotage Yuk-long’s machinations, killing Monk Blackie in the process. With help from Big Mouth and Sissy, Fishy and More lure Yuk-long into a forest, where a final battle unfolds. The decisive moment comes when Fishy and More, wielding their united strength, impale Yuk-long’s swords and unleash a spectacular explosion, ending his reign and finally bringing the long-running conflict to a close.
In the end, Fishy and More’s love and teamwork endure, uniting their destinies in a perilous, cinematic world where loyalty, deception, and sacrifice test every edge of their courage, and where the couple’s resolve to protect those they care about prevails over the dark schemes of the Villains’ Valley.
