As Marvel and DC have often topped the box office with PG-13 films, Fox in recent years has carved out its own corner with such popular R-rated superhero movies as the Golden Globe-nominated "Deadpool" and the Oscar-nominated "Logan."
Now, major franchises that helped first make Marvel Comics a publishing powerhouse in the '60s and early '70s can share the Disney stable - decades after the rights to these different properties were parted out to several studios, as each tried to gain big cash and traction in Hollywood.
Bryan Singer's "X-Men" (2000) deserves as much credit as any film for kicking off the current era of massive superhero franchises, eight years before the MCU dawned with "Iron Man."
Since the rise of Marvel's film universe, fans have clamored for studio crossovers to unite Marvel characters on the screen. One step in that direction has paid off handsomely in the past several years, as Sony struck a deal with Marvel for Spider-Man's solo and team-up movies. Marvel helped Sony revive its Spidey franchise, and the three films so far that have suited up Tom Holland as Peter Parker have grossed more than $4 billion worldwide combined.
Now, perhaps Disney can work similar magic with the Fantastic Four. The franchise's first two films did decent box office more than a decade ago, but in 2015, the third film was a creative and commercial dud.
But when it comes to Fox's successful titles, one question looms significant: Will Disney, given its family brand, be willing to release R-rated superhero movies - even under some sort of "new Disney" banner?
If Disney pressures "Deadpool" to dilute its four-letter language and double-fisted brutality, Ryan Reynolds's team might balk - and many fans might walk.
Look for Disney, as wise as any studio about turning superheroes into profits, to brand and market the migrating Fox properties in a way that retains their sense of being adult fare - even if the films can skirt an "R" rating and squeeze just under a PG-13 rating. Boundaries will be tested, but "Deadpool" is the only Fox franchise that has been released exclusively with an "R" rating.
Beyond that, the deal should excite Marvel comic-book fans. After all, who doesn't want to finally see an Avengers and X-Men crossover movie?
At last, the franchises are assembled.