The official trailer for Doctor Strange in the Multiverse of Madness was chock-full of mind-melting imagery and hints at a universe-spanning conflict involving Benedict Cumberbatch's Sorcerer Supreme and Elizabeth Olsen's Scarlet Witch. But the biggest moment occurs when Strange is handcuffed and escorted into a room by what looks like upgraded versions of Ultron. A mysterious voice says, "We should tell him the truth," as a figure enters into the frame. Although the figure remained shrouded in shadows, fans immediately pegged the voice as belonging to Patrick Stewart – who is best known for playing Professor Charles Xavier in 20th Century Fox's X-Men film franchise. But Stewart's (potential) role in the film also points to the formation of a team in Marvel Comics who could end up shaping the future of the Marvel Cinematic Universe - The Illuminati.
First appearing in New Avengers #7 by Brian Michael Bendis and Steve McNiven, the Illuminati's membership consisted of Strange, Xavier, Iron Man, Namor the Sub-Mariner, the Inhuman king Black Bolt, and Mr. Fantastic. They first gathered together when Iron Man suggested that the superhero community form a delegation similar to the United Nations in the wake of the Kree-Skrull war. The six eventually decided to meet in secret, keeping their existence as a group from their friends, family, and teammates.
The Illuminati were responsible for kicking off a number of Marvel events, including the decision to launch Bruce Banner into space after one of the Hulk's rampages leveled Las Vegas. They also tracked down and split the Infinity Gems among themselves so that nobody could utilize their power to do harm; convinced the godlike Beyonder to leave their universe; and told the Skrull empire that the Earth was off-limits. Eventually, things came to a head after the Hulk's exile and the drafting of the Superhuman Registration Act, with the group splitting up afterward.
The Illuminati's actions eventually came to haunt them, as the superhero community became divided over the Registration Act, leading to the Civil War storyline. The Skrulls had gleaned a way to replicate superhuman powers after their battle with the Illuminati, and launched a plan to conquer the Earth as they felt it was their birthright after Galactus destroyed their homeworld in Secret Invasion. And the Hulk, landing on the planet Sakaar and forced to fight in brutal gladiator battles, eventually came back to Earth to take vengeance on the Illuminati in World War Hulk. The criminal mastermind known as the Hood would also gain power over the Infinity Gems, leading to friction between Captain America and Iron Man when the Sentinel of Liberty discovered the Illuminati's existence. Nearly all of these storylines have influenced projects within the MCU; Civil War served as a major foundation for the story of Captain America: Civil War, while a Secret Invasion series is currently being filmed for Disney+. Elements of World War Hulk made their way into Thor: Ragnarok, as Thor finds himself on Sakaar and is forced to battle the Hulk in gladiatorial combat.
But a recent storyline involving the Illumanti may hint at a future storyline that the MCU has yet to adapt, and one that would fit perfectly with the events of the current series. In the relaunched New Avengers series spearheaded by Jonathan Hickman and Steve Epting, Black Panther – who originally warned the Illuminati that their actions would have devastating consequences - gathers the remaining members of the Illuminati, alongside the X-Men's Beast who stood in for a deceased Xavier and Captain America when a mysterious incursion leads to an alternate Earth colliding with theirs. The Illuminati resolve to handle future incursions by any means necessary – even wiping Captain America's mind when he protests. Eventually, this leads to the Secret Wars miniseries by Hickman and Esad Ribic, which finds the Multiverse destroyed and put back together by Doctor Doom - who gained godlike powers after confronting the beings known as the Beyonders.
This leads to Stewart's possible return as Xavier, which raises a number of questions about the Illuminati's presence in the MCU. Do they know about the Multiverse? And who else could be joining the X-Men's founder? Rumors have swirled online about Tom Cruise – who was first approached to play Tony Stark in Iron Man – making an appearance; the Ultron drones escorting Strange in the trailer certainly seem like something Stark would build. And could Reed Richards appear, pulling double duty as a member of the Illuminati and as a member of Jon Watts's take on the MCU's Fantastic Four?
And as for Secret Wars, the building blocks may have already been laid in Loki. In the first episode "Glorious Purpose", while Tom Hiddleston's God of Mischief is being brought before the Time Variance Authority for judgement, the TVA's mascot Miss Minutes (Tara Strong) narrates a video about a multiversal war that led to the creation of the "Sacred Timeline". Said multiversal war could be a prelude to a film that adapts Hickman and Esad's Secret Wars saga, especially since Loki showrunner Michael Waldron also penned the script for Multiverse of Madness. And with Joe and Anthony Russo proclaiming that Secret Wars is one of their favorite comic book stories and that they'd return to helm an adaptation for Marvel Studios if given the chance, perhaps the Illuminati's presence could lead to said adaptation.