Spider-Man (Tom Holland), Iron Man (Robert Downey Jr.), Drax (Dave Bautista), Star-Lord (Chris Pratt) and Mantis (Pom Klementieff) in "Avengers: Infinity War" from Disney and Marvel Studios Source: Walt Disney

In 2008, Marvel Studios turned the page on the comic book movie with "Iron Man," which became a smash hit. A decade later, superhero flicks are at another turning point. Walt Disney-owned Marvel will drop the curtain on the third act of an unprecedented 11 years of interconnected storytelling, which spanned 22 films. The studio has been virtually bullet-proof at the box office, but with some of the stars who built the Marvel cinematic universe expected to exit the film series, Disney faces a fresh set of challenges. Meanwhile, Warner Bros. is finally starting to close the gap with Marvel. After its own cinematic universe based on DC Comics sputtered under the direction of director-producer Zack Snyder, Warner is now gravitating towards standalone films, and away from Snyder's grim-and-gritty tone.

But it's the X-Men franchise at 21st Century Fox that faces the biggest potential change. The series has been going strong since 2000, but with Disney about to close its deal to buy Fox, fans may soon be bidding farewell to the onscreen X-Men they've come to know. The upshot: 2019 could be the most exciting year for comic book fans since at least 2014, when both Marvel and Warner announced a full slate of superhero releases across several years.

Marvel Studios: Looking to keep its crown

As the final phase of Marvel's magnum opus wraps up with "Avengers: Endgame" (May 3), fans are eagerly anticipating another big announcement. Marvel Studios President Kevin Feige says the company will shed light on its plans after "Avengers: Endgame." "This is really interesting because they have enjoyed unprecedented, ongoing, uninterrupted success with the formula," said Paul Dergarabedian, senior media analyst at Comscore. "Everyone loves what they're doing, but if it's the same thing over and over, that's where the superhero fatigue will set in," he added. The Avengers franchise is still one of the highest-earning in Hollywood. Last year's "Avengers: Infinity War" was the first superhero movie to earn $2 billion worldwide. If the studio opts to freshen up the roster — a common occurrence in comic books — it has some strong candidates.

In 2018, "Black Panther" became Marvel's highest-grossing movie featuring a standalone hero. Marvel's partnership with Sony, which holds the film rights to Spider-Man, yielded another major hit in 2017 with "Spider-Man: Homecoming." On July 5, Marvel will test Spidey's staying power — he's been rebooted twice — with the sequel "Spider-Man: Far From Home." Strong box office pre-orders for Marvel's newest and first female-led franchise — "Captain Marvel" (March 8) — point to another likely blockbuster. Marvel is also reportedly developing films based on Avengers member Black Widow and martial arts master Shang-Chi. The studio is also preparing sequels for franchises like "Guardians of the Galaxy" and "Doctor Strange." The critical acclaim and box office earnings for "Thor: Ragnarok" has sparked talk of a third sequel.

X-Men: All good things come to an end

Marvel Studios is also poised to reap an embarrassment of riches when Disney's deal to buy 21st Century Fox closes, possibly in the coming weeks. The acquisition comes with the rights to Marvel Comics' X-Men and Fantastic Four properties. At 19-years old, X-Men is the longest ongoing superhero series in Hollywood. The original trilogy wrapped in 2006, but Fox revived the franchise in 2011 with a series of prequels. The fourth prequel, "X-Men: Dark Phoenix," arrives in theaters on June 7, followed by "New Mutants" on Aug. 2. Though executives remain tight-lipped about their plans, the movies are widely expected to bring the series to a close. Conventional wisdom suggests Marvel Studios will start from scratch, folding the mutants into its cinematic universe.

But there's yet another question hanging over the series: What becomes of Fox's massively popular expansion into R-rated territory? In the last three years, Fox has found success with violent movies starring hard-edged heroes. Its two "Deadpool" movies and the Wolverine sequel "Logan" are three of its top four highest-grossing releases in the series of core X-men titles and spin-offs. Disney CEO Bob Iger has hinted at a path forward. Shortly after the deal was announced, he floated the idea of an R-rated brand to accommodate titles like "Deadpool." Dergarabedian thinks a sub-label makes sense, adding that killing off the adult-oriented films would be a blow to fans and theater-owners alike. "I'm hoping that the success of the R-rated Fox superhero films isn't lost in the future," he said.

DC Comics: The future is brighter than ever

Since launching its own cinematic universe in 2013, Warner has put up a string of box office successes. However, its DC Comics movies have mostly taken a drubbing from critics, and underperformed Marvel's top earners. Still, the tide could be turning. Warner executives decided to switch gears shortly before its troubled team-up movie, "Justice League", disappointed at the box office. Encouraged by the strength of 2017's "Wonder Woman," a World War I period movie, Warner is now focusing on standalone stories. There are signs the pivot is paying off. Last weekend, "Aquaman" became the first DC Comics movie to cross the $1 billion threshold at the global box office since "The Dark Knight Rises" in 2012.

"I think they're in a really good spot right now, and perhaps the lesson learned from 'Aquaman' and 'Wonder Woman' will carry forward," said Dergarabedian. "Every individual studio has their own identity, and they don't always have to chase what the others are doing." Warner's next superhero movie is an even bigger departure from the dark tone Zack Snyder struck in early installments of the DC cinematic universe. "Shazam!" (April 5) is an action-comedy about an orphan who obtains the power to transform into an adult hero. Shazam is portrayed by Zachary Levi, best known for portraying the titular character on NBC's action comedy "Chuck." DC will also test the waters with a release entirely disconnected from its shared universe. On October 4, "The Hangover" director Todd Phillips spins an origin story for Batman's legendary arch-nemesis in "Joker." Next year, Warner returns to the shared universe with "Wonder Woman 1982" and "Birds of Prey," featuring Margot Robbie as Harley Quinn, the breakout character from 2016's "Suicide Squad."

More change afoot