May 6, 2016 will be the biggest superhero showdown in history.

Marvel originally staked out the date for an as-yet-untitled Phase 3 movie. Warner Bros. later shifted their "Man of Steel" sequel (tentatively titled "Batman vs. Superman") to the exact same date, after delaying it from July 17, 2015.

Marvel Cinematic Universe mastermind Kevin Feige is unafraid of the heavy competition and says the studio will go ahead with their plans for the date.

"We're certainly keeping the date there and we'll announce what that movie is, I assume, in the next few months," Feige told Slashfilm.

If both movies stay put -- and it's likely that one will flinch -- it will directly pit comic book titans Marvel and DC against one another. 

The 2016 Marvel movie is, for now, still a mystery, and there's been speculation that it could be "Thor 3," "Captain America 3," a standalone Black Widow film, or a new property entirely. It likely won't be the previously announced "Doctor Strange," which Feige has indicated won't make it to theaters until 2017 or so. 

When asked if Marvel will announce the new film at Comic-Con in July, he responded, "I’d love nothing more than to be able to announce them all there. But if it’s ready beforehand, we’ll probably do it beforehand. If it’s not ready then, we’ll do it after."

Meanwhile, Marvel's "Captain America: The Winter Soldier" opens in April, with "Guardians of the Galaxy" following later in the year. "The Avengers: Age of Ultron" and "Ant-Man" will hit theaters in 2015.  

The Zack Snyder-directed "Man of Steel 2" stars Henry Cavill, Ben Affleck, Gal Gadot, Amy Adams, Jesse Eisenberg and Laurence Fishburne.

If Marvel and DC do end up opening movies on the same day, which one would you plan on seeing first?