The first movie in a superhero movie franchise (or the only movie in an attempted franchise) always ends with the hero fighting a climactic battle against a villain who is somehow connected to the hero's origin, thus giving the movie a sense of connectedness and closure.
This happens in part because movies, especially ones not certain to start a franchise, need to hold up on their own as a single cohesive plot. If a film tells a superhero's origin, that origin generally needs to be integrated into the rest of the plot of the movie, and the best way to do that is to involve the main villain in the origin.
In adaptations of comic books, this often involves rewriting the hero's origin to create a suitable connection.
- In nearly every version of Astro Boy, the precipitating incident for Astro's origin is a traffic accident. In the American movie version, it's a robot superweapon test gone wrong, and Astro winds up fighting the robot superweapon at the climax.
- Batman makes the Joker into the guy who shot Bruce Wayne's parents and inspired him to fight crime. They fight at the end of the film.
- Batman Begins seemed to avert this, as Bruce Wayne's parents are shot by a random mugger who dies before Bruce becomes Batman, but the Big Bad claims indirect responsibility during their penultimate face-off, so the climactic battle is an example after all.
- Blade ends with the eponymous hero facing off against Deacon Frost—the vampire who bit and turned his mother (responsible for Blade's origin by proxy, since she was pregnant at the time).
- Captain America (1990) and Captain America: The First Avenger make the Red Skull into a Psycho Prototype of the super-soldier treatment.
- In Fantastic Four Doctor Doom was also on the flight which gave them their powers, gets powers of his own, and is the Big Bad they fight at the end.
- Green Lantern: Hal Jordan fights Parallax, who was responsible for the death of Abin Sur that resulted in him being given the green lantern to begin with. (In the comics they were unrelated.)
- Hulk's climax involves Hulk fighting against Banner's father, who was partially responsible for making Banner into the Hulk.
- Iron Man: Tony Stark creates the first Iron Man suit to escape after being kidnapped. The climactic battle is Iron Man versus the guy who hired the kidnappers in a bootleg Iron Man suit.
- The Phantom starts with Kit Walker already established in the role of the Phantom, but there is still a subplot about him having unresolved business with the man who killed his predecessor. That man is The Dragon, and they fight in the film's climax.
- The Punisher (2004 version starring Thomas Jane): Howard Saint orders the massacre of Frank Castle's entire family after his son is killed in an FBI drug bust that Castle was involved in as an undercover agent. The rest of the film involves Castle adopting the identity of the Punisher for the express purpose of avenging his family. He does this by systematically eliminating every single important member of Saint's criminal empire (including Saint's wife and second son) which ultimately culminates with Castle killing Saint himself.
- Thor: Loki is ultimately revealed to be behind the Frost Giants who snuck into Asgard, which started the chain of events that led to Thor being stripped of his powers and exiled to Earth. After living among humans and learning the proper humility, Thor regains his powers and returns to Asgard where he defeats Loki, who by that time had usurped Odin's position as the ruler of Asgard.
- X-Men: First Class counts, if you consider Magneto an Anti-Hero throughout the film and a Fallen Hero at the end. Sebastian Shaw is the person who turned him into what he is, and Magneto kills him for it as part of his Start of Darkness.