Much like the anti-Qing struggle referenced in the first night of A Very Shaw Brothers Christmas, the legend of the destruction of the Shaolin Temple is a common narrative backdrop in kung fu movies. Respectively they're kind of akin to the role the Civil War and Little Big Horn play in American Westerns. The Temple story is also a subset of the larger Qing-Ming war, as in addition to being a Buddhist monastery with a sideline in innovative kung fu techniques, the Temple was also, according to legend, a center for anti-Qing activism in the decades after they took over the country (late 1600s-early 1700s). Central to the story is the character of Pai Mei (or Bak Mei), one of the five elders who survived the burning of the Temple and in some versions of the story brought about its destruction by collaborating with the Qing (he's the Shaolin Judas or Benedict Arnold). You might recognize the name from Kill BIll Vol. 2, where Pai Mei is the white-robed kung fu master who instructs all of David Carradine's assassins, including Uma Thurman. In that film, Pai Mei is played by the great Shaw Brothers star Gordon Liu, made up with a long white beard and eyebrows ("Pai Mei" apparently means "white eyebrows").
Gordon Liu plays a small but notable role in Executioners of Shaolin, directed by his adopted brother Lau Kar-leung. The two would of course make several great films together over the next decade, the greatest of which was made the next year, 1978's The 36th Chamber of Shaolin, which takes place earlier in the Temple's history and chronicles its entrance into the wider political struggle. Executioners starts at the end of the battle for the Temple, with a fight between Pai Mai (played by Lo Lieh) and one of the temple masters played out before an abstract red backdrop as the credits roll, a Lau trademark. After Pai Mai kills him, we cut to various monks fleeing the destruction and Gordon Liu gets his standout scene as he takes on the Qing forces so his brothers can escape. From then, the film follows the life of Hung Hsi-kuan, played by The Flying Guillotine star Chen Kuan-tai as he practices for 20 years or so to avenge his master's death.
But here's where the film gets weird. Instead of simply training and working out the various martial tactics he'll need, as in many another kung fu film (Shaolin Mantis, say, or in the best case, The 36th Chamber of Shaolin) or the search for a kind of spiritual enlightenment that'll provide him with untold power (The Tai Chi Master or 8 Diagram Pole Fighter), Hung meets a nice girl, gets married and has a son. The whole middle section of the film is in fact a marital comedy. Hung meets Ying Chun, played by Lily Li, when he and his fellow fugitive monks are posing as street performers and keep interrupting her own performances. They argue over whose kung fu is superior: his Tiger Style or her Crane Style and end up falling in love. Over the next decade, while she does the laundry and raises their son and he trains to defeat Pai Mai, he repeatedly rejects her suggestion that he learn some of her Crane Style too. When ten years have gone by, he challenges Pai Mai and loses, but escapes. Pai Mai's secret is that he can move his vital points (attacking said points are the key to defeating him) from his groin to his head at will, such that when Hung (and his master before him) kick Pai Mai there, their foot gets stuck in the empty space where his testicles should be. Hung goes back to the drawing board (in this case, a copper statue filled with marbles, I'm unclear how this works) and figures out that he needs to attack Pai Mai only at certain times of day. He trains for seven more years, again refusing to adopt elements of his wife's Crane Style, challenges him again and loses.
Here the son, Wen-ding, enters the picture. By his father's orders, he's only been trained in his mother's kung fu style. But the two of them find an old moth-eaten Tiger Style manual and Wen-ding trains for a year to take on Pai Mai. By using a combination of both his parents' styles, Wen-ding is able to defeat Pai Mai. So, the unstoppable villain is a man who can willfully castrate himself. A man alone is unable to defeat him, no matter his skill at the manly (Tiger) style of fighting. Only through the combination of male and female (Crane) styles can he be bested. Yin or Yang alone cannot defeat the void, the absence of Yin or Yang, it needs to be a balance of both together.
I'm not sure how much of the Hung story is original and how much based in legend. It sounds very similar to the stories about Fong Sai-yuk, whose mother trained him in kung fu (she was the daughter of one of the Five Master of the Shaolin Temple who survived its destruction) while his father was active in anti-Qing resistance. In one version of the legend, Fong Sai-yuk is killed by Pai Mai. Jet Li played Fong in a pair of excellent films from the early 90s, but neither of them make reference to Pai Mai or the Temple, as far I as can remember.
Lau would return to the martial arts as marital comedy style of film to great effect a few years later in Heroes of the East (aka Shaolin vs. Ninja) in which a married couple argue over which nation's martial arts are superior, his Chinese or her Japanese. But I don't think I've seen anything like the transgressive view of gender on display here from Lau before, or in any other kung fu film, for that matter. Not until the gender-bending of Ching Siu-tung's Swordsman II at least, and even that film is pretty misogynistic.
