There's one major X-Men storyline that Marvel Studios should avoid adapting after mutants have been properly introduced to the MCU. The film rights to mutants and the X-Men reverted to Marvel after Disney's 2019 acquisition of Fox, raising anticipation for the introduction of mutants in the MCU. With an alternate universe's Professor X cameo in Doctor Strange in the Multiverse of Madness, the confirmation of Kamala Khan's status as a mutant in Ms. Marvel, and a Wolverine tease in She-Hulk: Attorney at Law, it won't be long before mutants are interacting with already established MCU superheroes.

Prior to Marvel regaining the rights to the mutants, Fox produced an X-Men film series spanning 13 films over 20 years, though many of these projects were met with mixed responses from critics and audiences alike. The franchise adapted some of the most well-known stories featuring the X-Men from Marvel Comics, including X-Men: First Class, X-Men: Days of Future Past, and the Old Man Logan comic run for Logan. While these three projects were positively received, there's one storyline that has been adapted more than any other and has been met with an overwhelmingly negative response each time.

Related: Huge MCU Theory Proves Why Mutants Have Been Missing

Both 2006's X-Men: The Last Stand and 2019's Dark Phoenix films adapted the Dark Phoenix Saga from Marvel Comics, with neither doing the comic storyline justice. The comic arc sees Jean Grey, a member of the original X-Men team, inherit the cosmic Phoenix Force, which results in the hero's corruption, causing her to battle with the X-Men. While this narrative is one of Marvel Comics' strongest moments, the story never managed to translate well to the screen. With mutants becoming more prevalent in the MCU, this is one storyline that Marvel Studios should actively avoid repeating.

Why Marvel Should Avoid The Dark Phoenix Storyline

Taking into account that the Dark Phoenix Saga has already been adapted twice over at Fox, it's likely that avid viewers of Marvel films are already familiar with the storyline and don't need to see it played out again. Marvel Studios have taken this approach already with the origin story for Tom Holland’s Spider-Man in the MCU, with Spider-Man: Homecoming making the conscious decision to focus on a later point in his career instead of repeating something which had been adapted twice already in 2002 and 2012. There's no doubt that if Marvel Studios did decide to adapt the Dark Phoenix Saga for the MCU, they'd fare infinitely better than the attempts at Fox, but the story will get old very quickly, and there are plenty of other strong X-Men storylines that could be adapted in its place.

On top of this, many of the plot points from the Dark Phoenix Saga have already been recycled into other MCU projects, most prominently in Marvel Studios' first Disney+ series, WandaVision, which rules out an MCU Dark Phoenix story due to their striking and surprising similarities. Since many of the key plot points have already been used in various MCU projects, it would be completely unnecessary and slightly jarring to reuse these moments again just with a new roster of heroes. The X-Men have a rich history in Marvel Comics, with hundreds of story arcs ready to be adapted to film - there's no need for Marvel to tackle the Dark Phoenix Saga once again.