Marvel Studios has the Avengers and the entire cinematic universe, Warner Bros. is building towards the Justice League. Sony is laying the groundwork for the larger Spider-Man universe, and Fox is also interested in doing the same thing with the superhero properties they have the film rights tonamely the X-Men and the Fantastic Four. Theyve already announced that theyre planning for an eventual crossover film between Marvels First Family and the mutants. The question, of course, is how. Enter Franklin Richards, the son of Mr. Fantastic and the Invisible Woman. Who has vast, godlike powers. And is also a mutant. Hes also a central figure in Days of Future Present, a crossover that involves the X-Men and the Fantastic Four. Oh, and in the Days of Future Past timeline, he and Rachel Summers are an item and in a possible future, they give birth to a powerful villain named Hyperstorm. If Fox is set on an X-Men/Fantastic Four crossover film, then Franklin Richards seems like the perfect figure to bring that about. Which means that we could see Franklin appear in X-Men: Apocalypse, even if its only in a post-credits stinger. Of course, this could also be a long shot. Fox may not want to introduce Franklin into the equation when theyre trying to go with a much younger Fantastic Four.