Back in the 70s all the comic book superheroes were the standard truth-justice-and-the-American-way paragons of an ideal savior. I'm not familiar with Japanese manga at the time but I hear they were similarly based on an idealized heroic/nationalistic template (though Japanese manga has always been a good 20 years ahead of the DC/Marvel stock). As far as mainstream movie adaptations go, probably the first dark(-ish) superhero we got was Tim Burton's rework of Batman in 1989...though more or less honorable, he had some dark psychological twists to his noodle. I'd say the first truly dark superhero story to hit western theaters was The Crow (1994), a killer from the grave hell bent on avenging his lover's rape and murder, dispatching his victims in sadistic ways.

But let's rewind 20 years and take a look at Lady Snowblood. Her backstory begins before she was born: a young family was ambushed by political profiteers, the man was skewered a dozen ways as the child was slaughtered and the woman was raped for 3 days straight. Oh it gets worse, but I won't spoil anything except to say the woman ends up becoming a self-professed slüt having sex with all her torturers so she can spawn a demon child. And that, kiddies, is how Lady Snowblood was born.

The movie then takes us along Snowblood's twisted path to fulfill her prenatal vendetta. She is barred from having her own life or any attachments & emotions other than cold blooded hate toward her targets. This is the only way she can complete her heartless mission even though it's hurting innocent people along the way.

Did I mention this was 1973??? At the time in America we were getting Linda Carter's Wonder Woman and even 5 years later we'd get Christopher Reeve's Superman, the ultimate caped boyscout.

Lady Snowblood was wayyyyyy ahead of her time. Even today the mainstream Marvel superheroes are privileged little brats compared to this chick!