SPOILER WARNING!
This post contains information that spoil elements of Batman v Superman: Dawn of Justice, along with Man of Steel, Death of Superman, and The Dark Knight Returns

The battle between Superman and Batman on the big screen is inspired by the comics The Dark Knight Returns, written and penciled by Frank Miller. Which isn’t at all surprising when you consider that Zack Snyder, the director of the film, also directed the movie-adaptations for Watchmen and 300; two comics that were both written by Miller. But there are synergies between the two that are a bit too powerful to stay within the established boundaries of the main characters.

I think it must have started with Christopher Nolan’s version of The Caped Crusader in his movies Batman Begins, The Dark Knight, and The Dark Knight Rises. These movies were very dark and took the characters and villains to a place we had not seen in the movies before. Most iconical being the portrayal of the anarchistic Joker, by Heath Ledger. This was a fresh take on the well-established superheroes and foes, as most interpretations before had been very colorful and somewhat campy. And it works for Batman, because he is a dark character and he resides in a dark world. But the executives at Warner Brothers and DC Entertainment, the companies that own the cinematic rights to the DC Universe, must have seen the success of these three movies as a sign that people want dark movies about superheroes. Which isn’t really true, as we’ve seen with Marvel and the MCU, that are very adventurous and mostly true to source. But be it out of spite to differ themselves from Marvel, or just misinterpretation of the audience, DC decided to keep the dark tone as they started their own venture to build a cinematic universe.

A pivotal moment that purposely separated the DCEU from the comics

So Zack Snyder got the job to direct the first movie to kick off what is to be called DCEU, DC Extended Universe, the new version of Superman in Man of Steel. And in his first go, in the mov he takes some of the basics of the character’s origin story and gallery of characters and brings it into the modern world. But in the third act he does something that utterly destroys what the character has previously been built up to represent over the last sixty years.
Superman kills.
More than ever before the collateral damage of Superman’s engagement with his foe is presented and In a pivotal moment that may have been purposely meant to separate the DCEU from everything that the comics had forged into the very core if its being, Kal-El breaks the neck of General Zod to save the future of his adoptive planet. He then proceeds to tell the government that he will operate entirely on his own. A big leap from the Captain America-esque, boy-scout version that we’ve seen previously.

Batman v Superman: Dawn of Justice start with a different view from the third act of Man of Steel, with buildings collapsing and the consequences of a battle of that magnitude and a spaceship crashing being presented again and Bruce Wayne in the middle of the crumbling city. Since the movie only has so many minutes to develop characters and relationships, this is used as motivation that shoulders Batman with many characteristics that have previously been carried by Lex Luthor in the comics; the anxiety that Superman is powerful enough to destroy the entire planet and needs to be stopped. Lex. portrayed by Jesse Eisenberg, on the other hand is transformed from a charming, calculating, power-hungry sociopath to a more clearly villainous psychopath that is a closer approximation of The Joker than Luthor from the comics. But that doesn’t forgive the next sin against the source-material, as Batman not only seem to kill his opponents, he actually does so with guns; a weapon that goes against every fiber of the character as proposed by his origin story.

Dark Knight vs Man of SteelWhen the headliners finally collide we get treated to a great homage to what took place in The Dark Knight Returns, which previously pitted the two combatants against each other in a battle of superhuman powers versus human will, ingenuity and martial arts. But where the comics feature the “death” of Bruce Wayne, the movie instead goes on to the two joining forces and the franchise spends one of Superman’s deadliest foes in a spectacle-filled third act that duct tapes the titular heroes together with Wonder Woman, whom could have gotten a better presence in the movie, as they essentially play out the ending of Death of Superman. Doomsday makes an appearance, to give our heroes an enemy of some actual magnitude, and Kal-El goes under while taking the monster down. Bruce and Diana attend their new-found friend’s funeral and in a last second shot we get a glimpse that Superman may not actually be gone forever; also evidenced by his casting in the upcoming Justice League movies. But the scene itself is a reminiscent mix of scenes from The Dark Knight Returns and Death of Superman.

Even if I really enjoyed the movie and the universe that they’re establishing I had to remind myself continuously of one thing. And whether you place the blame on WB, DC, Snyder, or David Goyer, the guy that actually wrote these first installments, you may need to teach yourself the same thing: This is not the DC you grew up with. This is Snyder’s Batman v Superman.