How Franklin Richards, the power cosmic and Doctor Doom's appearance in "The Fantastic Four: First Steps" credit scene affects "Avengers: Doomsday."

In Marvel Comics, Doom’s fixation on Franklin is legendary. He views the boy’s near-limitless powers as the key to creating and ruling Battleworld, a twisted reality of his own making as seen in Secret Wars.

A good chunk of Doomsday could focus on a clash between Avengers and X-Men with RDJ’s Doom cackling in the background, with a kidnapped Franklin by his side. The premise certainly gives the Fantastic Four a reason to breach their multiversal walls and zip over to 616 to meet the New Avengers.