Batman has always been one of the most intense crime fighters in the DC Universe. Wanting to strike terror into the hearts of criminals, he not only delivers a beating to the bad guys, but does his best to make sure they’re too frightened to ever return to committing misdeeds. However, after decades of battling evil in the DC Extended Universe, Bruce Wayne has become so hardened that in Batman v Superman: Dawn of Justice, he’ll take his crusade to the next level.
While touching on the conflict between Batman and Superman in both their superhero and civilian lives, producer Charles Roven explained to Empire just how far the Caped Crusader is willing to go. As he put it:
Batman is not giving people a chance... He is more than a vigilante. He has become not only the cop, if you will, he has also become the jury and executioner.
This new approach is part of Ben Affleck’s Bruce Wayne being tougher and having "seen the worst of what man can do." Roven also mentioned how Bruce has lost people close to him, and "not necessarily from old age or disease." These early deaths include his parents being gunned down by a mugger and a Robin (most likely, but still not officially announced, Jason Todd) who was killed by The Joker. Now Batman’s at the point where he’s surpassed mere vigilante and going through the entire justice system on his own, and as Clark Kent noted in the last trailer, civil liberties are being trampled on. You can already tell just how brutal he’s getting just by the look of that brand he’s putting on Gotham City’s criminal element, as seen below.
In terms of his grudge towards Superman, Bruce was in Metropolis during the Man of Steel’s battle with Zod. He witnessed firsthand the destruction that city endured and how many lives were lost, including the people in a Wayne Financial building. Add a "Knightmare" on top of that, and Bruce has become so paranoid about the Kryptonian that he’s willing to do whatever it takes to make sure he doesn’t pose a danger to mankind, even if it means "destroying him."
Although Batman has killed before, namely in his earliest appearances and the Tim Burton movies, most modern stories depict him as unwilling to take a life, though he’ll pretty much go to any other lengths. So to hear that Batman may take a life in Batman v Superman: Dawn of Justice is undoubtedly disconcerting to some fans. Obviously we know Superman and Batman will eventually make up, but it definitely sounds like this is one of the darkest interpretations of the Dark Knight yet.
Gotham City’s shadowy protector will be fully unleashed when Batman v Superman: Dawn of Justice is released on March 25.