Things In The X-Men Franchise You Only Notice After Watching More Than Once

Before Marvel Studios launched its enormously successful Marvel Cinematic Universe, 20th Century Fox had a thriving superhero universe of its own with its long-running "X-Men" film franchise. Launching in 2000, the movies followed the eponymous superhero team as they used their incredible powers to defend a world that hates and fears them, often from fellow mutants looking to subjugate humanity. The films brought fan-favorite characters like Wolverine, Nightcrawler, and Deadpool to the big screen for the first time while kickstarting the careers of many prominent members of its casts, including Hugh Jackman.

With over a dozen films in Fox's franchise, there are certain nuances, small details, and plot holes that are only truly noticeable to audiences after multiple viewings of each installment. Here are things that may only occur to viewers after repeated sittings, from character traits that are dropped without explanation across the series to glaring inconsistencies with the movies' overarching timeline.

"X2" revolves around Colonel William Stryker carrying out his longstanding vendetta against mutants and Charles Xavier after years of extensive planning and preparation. As Mystique hacks into Stryker's private database to learn how to free Magneto from federal custody, she discovers the Colonel's files on other mutants. The names and folders she finds listed are a veritable treasure trove of "X-Men" Easter eggs and deep cuts that practically demand repeat viewings in slow-motion to catch them all.

Among the mutants listed in Stryker's database are many characters that would prominently appear in later "X-Men" movies, including Remy LeBeau, the Maximoffs, Elizabeth Braddock, and Jamie Madrox. Other major names listed that would not go on to appear in the film series are Garrison Kane, Omega Red, and the Von Strucker twins, each of whom has an antagonistic history with the X-Men in the comics. The X-Men have one of the most extensive lores to draw from in the comics, and Stryker's database offers a fuller glimpse at the deep bench of characters available to potentially include.

T.H. White's 1958 literary collection "The Once and Future King" compiles and updates the legend of King Arthur and the Knights of the Round Table. With its themes revolving around rises to power and crises of leadership, the novel has subtly appeared throughout the "X-Men" films. Specifically, both Magneto and Professor X are shown to have an appreciation for White's novel, with both mutant leaders seen with the book.

While locked away in federal custody in "X2," Magneto is seen reading "The Once and Future King" in his cell before being attacked by his cruel guard. At the end of the film, Professor X uses the novel to lead a class discussion with a group of students back at the X-Mansion. The text's continued relevance resurfaces in "X-Men: Apocalypse," with Professor X reading passages from the novel to his class in 1983. To quietly underscore the connection to "X2," Charles is reading from the same edition seen in the 2003 film in "Apocalypse."

Colonel William Stryker is a recurring antagonist across both timelines of the cinematic universe, often targeting Wolverine to transform him into the ultimate, mindless weapon. Stryker's connection to Logan is revealed in "X-Men Origins: Wolverine," with the colonel going rogue and casually murdering a general who questions the efficacy and morality of the Weapon X program. The mid-credits scene to the prequel has Stryker taken into military custody over the general's murder, raising questions at how he was able to resurface with the president's support decades later in "X2."

The "First Class" timeline only makes Stryker's story more confusing and convoluted, starting with "Days of Future Past," ostensibly set before "X-Men Origins: Wolverine." With the timeline altered, Mystique disguises herself as Stryker to rescue Wolverine from the bottom of the Potomac River only for Stryker to be seen experimenting on Logan years later in "Apocalypse." The discrepancy between Stryker's predicaments across subsequent movies is never explained, causing some of the series' most confusing plot holes.

During the climactic battle in "The Wolverine," Logan confronts Ichiro Yashida, a friend he saved in Japan during World War II who is trying to steal the mutant's healing factor for himself. Using the advanced Silver Samurai armor, Yashida is able to cut off Logan's adamantium claws with a superheated katana only for Wolverine's bone claws to grow back in time for him to kill Yashida. In a mid-credits scene, Logan is shown to still possess his bone claws when he faces Magneto though this detail is glossed over in "X-Men: Days of Future Past."

Set eight years after the mid-credits scene in "The Wolverine," Logan is revealed to have his adamantium claws restored in the post-apocalyptic era of "Days of Future Past." There is no explanation given within the film itself for the change, with the restoration not even mentioned by the characters themselves. Director Bryan Singer speculated that Magneto may have personally recoated Wolverine's claws with metal as part of their reconciliation against a common enemy viewers watching closely can see the change in claws between films for themselves.

Unfortunately, Jubilee is far from the only X-Men character to have an inconsistent track record across the Fox film series, both in regards to casting and timeline placement. The telepathic superhero Psylocke has had an uneven history on the big screen ever since she was first mentioned in Stryker's database in "X2." Meiling Melancon plays a version of the character in "The Last Stand," boasting a completely different power set than the comic books, before she is unceremoniously disintegrated by the Dark Phoenix in the finale.

A Psylocke appearing much more closely to the comic book source material appears in "Apocalypse," played by Olivia Munn, as one of Apocalypse's recruits. This version of the character not only features a costume and powers that align with the classic character but survives the climactic battle against the X-Men and escapes to parts unknown. After seeing Psylocke's appearance in "Apocalypse," viewers may want to revisit her radically different role in the original timeline to observe the discrepancy in full.

With its 20th-century setting, complete with cellphones and pop culture references, one can infer that the "Deadpool" movies take place in the 20th century like the original run of "X-Men" films. This timeline placement is underscored by Wade Wilson teaming up with Colossus in both films, a character only seen in the X-Mansion in movies set during present day. However, a blink-and-you-miss-it gag in "Deadpool 2" raises questions about when exactly the "Deadpool" movies take place, with the joke breaking timeline continuity in addition to the fourth wall.

While walking through the X-Mansion, Wade cracks that the normally bustling superhero school and headquarters is always deserted whenever he visits, likely due to budget issues behind-the-scenes. Deadpool is inadvertently proven wrong when he walks by a room filled with the "Dark Phoenix"-era X-Men who quietly closes the door to avoid being annoyed by the Merc with a Mouth. With "Dark Phoenix" set in 1992, the inclusion doesn't necessarily make chronological sense but, given Deadpool's penchant for irreverential self-aware humor, the punchline is more important than the logic.

With the film series coming to an inauspicious end with 2020's "The New Mutants," several plot threads introduced in "X-Men" movies never received a proper resolution. One of the most glaring examples of this is the post-credits scene of "Apocalypse," which sees shadowy figures from the Essex Corporation obtaining DNA samples from Weapon X. The only other follow-up to this scene takes place in "The New Mutants," with the Essex Corporation behind the detainment of the main characters in the movie for nefarious purposes.

By the end of "The New Mutants," the Essex Corporation remains at large in the aftermath of the heroes escaping from the remote experimental facility. In an interview with Yahoo! Entertainment, Jon Hamm revealed he was approached to appear in "The New Mutants" as Nathaniel Essex to set up a larger villainous role before the part was cut from the film entirely. With the rights to the X-Men now with Marvel Studios, the Essex Corporation references in "Apocalypse" and "The New Mutants" offer a small glimpse at how the film series could have progressed.