The two popular comic book heroes are set to face-off against each other in “Batman v. Superman: Dawn of Justice.” A new report explains what secret weapon Batman/Bruce Wayne will use against Superman in the movie. [Spoiler alert]

Comic books fans know that Superman is vulnerable to Kryptonite, so fans have long speculated that Batman will use Kryptonite in the forthcoming film. A report by Umberto Gonzalez at Heroic Hollywood now reveals that Batman will use a Kryptonite-laced spear in the movie.

The movie's trailer reportedly has a scene in which Batman can be seen holding the weapon -- but the picture shows the character from a distance at night and viewers are not able to see what he was holding. Some fans speculated that the character will use a rifle in the movie and, according to the report, that may still be true.

Addressing “complaints” about the trailer of the movie being too dark, Warner Bros. President Greg Silverman spoke to the Hollywood Reporter and explained the approach to the movie. “There is intensity and a seriousness of purpose to some of these characters,” Silverman said. He added that the filmmakers at DC were making movies “about superheroes” and they “aren’t making superhero movies.”

Silverman also said that the DC movies will contain humor and described this element to be an “important part” of the movies. When asked about what differentiates DC from Marvel, Silverman said that the viewers will see the difference in forthcoming movies like “Batman v. Superman: Dawn of Justice,” “Suicide Squad” and “Justice League.”

Marvel has had one success after another with its superhero movies. The movies from the studio include standalone movies like “Iron Man” and “Thor” and the fans also get to see all the superheroes together in movies like “The Avengers.”

“Batman v. Superman: Dawn of Justice” will feature a range of superheroes and villains. Apart from Bruce Wayne and Clark Kent, the movie will introduce Wonder Woman and Aquaman. The movie is slated to be released in March 2016.