Fox's X-Men film franchise introduced a lot of good things to contemporary cinema, but that's not what most people will remember after Marvel Studios introduces mutants into the Marvel Cinematic Universe. They'll remember the franchise for its tangled timelines, its failure to explore most of its characters outside of Wolverine, Xavier and Magneto and last, but not least, for its tendency to tease stories that were ultimately never told, or, in the case of Dark Phoenix (directed by Simon Kinberg), told multiple times, disappointingly.
But what about those untold stories? One of the best examples is in the franchise's various attempts to introduce Nathaniel Essex, better known in the comics as the twisted Mister Sinister.
The first time the franchise ever even mentioned his name was at the very end of X-Men: Apocalypse (directed by Bryan Singer), when genetic material from the Weapon X facility was taken away in a briefcase bearing the name "Essex Corp." The next film in the franchise, Logan, actually included Mister Sinister in the film's early stages of development, something early plans for the upcoming The New Mutants also featured. Finally, we saw his name again in Deadpool 2 with the briefly mentioned Essex House for Mutant Rehabilitation.
While all of these mentions allude to Mister Sinister's character in various ways, nothing ever really came of them. They're just Easter eggs (and a fantastic opportunity for Marvel Studios).
Right now, plenty of fans are still reeling from the failure of the X-Men franchise to adapt "The Dark Phoenix Saga," one of the most well known stories from the comics, not just once, but twice. More than a decade before Dark Phoenix, Fox released X-Men: The Last Stand, and it too is seen as a failed attempt at adapting the famous storyline. It is highly unlikely that the MCU will bring yet another adaptation of "The Dark Phoenix Saga" to the big screen, regardless of whether or not Marvel Studios is capable of doing the plot and characters justice.
It's a shame because the Dark Phoenix as a villain carries so much storytelling potential. Her existence almost demands meaningful exploration of all the characters involved in her story. She would allow the story world to expand and, of course, her presence would call for an epic confrontation resulting in a huge CGI fight sequence, as is almost customary among superhero films.
Thankfully, there is one other classic X-Men villain that can offer all of that and, as we mentioned, Fox never got (or took) the chance to utilize him. Mister Sinister is ripe for introduction, and it's something Marvel Studios should take advantage of, if for no other reason than to make a statement: That the X-Men mythos is in safe hands now and that the studio will not make the mistake of wasting such potential. And Mister Sinister is full of potential, if the comic books are any indication.
The first time the X-Men and readers were introduced to Mister Sinister was in the "Mutant Massacre" crossover event, although no one knew it at the time until Psylocke uncovered the fact that the Marauders slaughtering mutants were actually being led by someone behind the scenes.
That's who Sinister is, the twisted scientist orchestrating events from the shadows. As revealed in The Further Adventures of Cyclops and Phoenix (written by Peter Milligan, artwork by John Paul Leon, Klaus Janson and Kevin Somers), Nathaniel Essex wasn't always a mutant supervillain. He was just a man born in the 19th century who rose to prominence through his work in the field of genetics. He was obsessed with Darwinism and perfecting the human race. Eventually, it turned him into the object of ridicule among academics, but that didn't stop him. He continued to experiment, going so far as to work on kidnapped Morlocks and conduct experiments on the corpse of his four-year-old son, to his wife's horror.
It was the mutant Apocalypse that turned Essex into Mister Sinister, through the use of ancient, alien machines. Sinister was now a seemingly immortal creature wielding extraordinary power, which has only increased over the centuries as he kidnapped mutants and acquired their powers through genetic tampering. Even with powers ranging from psychic abilities to energy blasts, Sinister prefers to manipulate people, and that's something he does incredibly well. In fact, because of his age, he's been able to manipulate and observe the development of entire bloodlines, as he did with the Rasputins, beginning with Grigori and ending with Colossus. Then, of course, comic book fans will know of his involvement in the life and family of Nathaniel Summers.
Clearly, Mister Sinister is a formidable opponent, the kind that the MCU needs if it wants to continue building extensive sagas. The twisted ideology and modus operandi of Sinister isn't too far off from Thanos', in that they both provide solid bases for multi-film plots, and the character himself would no doubt prove to be just as memorable than the Mad Titan, if not more so.
It's all this potential that compelled filmmakers to consider him numerous times throughout the construction of the X-Men film franchise. It's so clear to some that award-winning actor Bryan Cranston -- known for his work on Breaking Bad -- has expressed heavy interest in playing Nathaniel Essex in a live-action adaptation. The actor once explained that it was because he wanted to play "an antagonist a fraction smarter than the protagonist, never dumbed down to give the hero an easy win. That’s frustrating and boring to watch."
That is exactly why fans adore the supervillain. He's always ahead of the protagonists. He keeps them on their toes and, whenever he's involved, we get to see what the heroes are really made of, what keeps them going. Villains like him keep superhero stories rich and intriguing and it's why -- despite the fact that Marvel comic books are overflowing with a variety of different characters -- Nathaniel Essex continues to rank highly among supervillains. It's no wonder. If we just take a look at live-action adaptations in the MCU, we can see that some major antagonists aren't too distinct from others.
It'll be at least five years until we see the X-Men in the Marvel Cinematic Universe. When that happens, we can't be certain that the mutants will find themselves embroiled in a story arc as epic as the "Infinity Saga." We can only hope that Marvel Studios proves that the Marvel Cinematic Universe is capable of accomplishing everything Fox failed to do with their largest superhero franchise. To do that, the MCU can use any one of the colorful costumed villains available in the comics, though few could ever match Nathaniel Essex. It's almost unquestionable that the fans, the X-Men and the MCU need a villain that is distinctly sinister.