The MCU’s Scarlet Witch and Quicksilver could be connected to the X-Men if one major villain theory turns out to be true in Marvel Studios’ future.

The introduction of one iconic villain in Marvel Studios’ upcoming X-Men reboot could answer major questions concerning the origins of the Scarlet Witch and Quicksilver in the MCU. Elizabeth Olsen and Aaron Taylor-Johnson debuted as Wanda and Pietro Maximoff, respectively, in the mid-credits scene of 2014’s Captain America: The Winter Soldier, but made their full debuts in 2015’s Avengers: Age of Ultron. While Pietro Maximoff’s Quicksilver unfortunately met his demise in Age of Ultron, Wanda Maximoff has had a transformative career in the MCU, leading to her embracing her identity of the Scarlet Witch and fully realizing her remarkable power.

From their Marvel Comics debut in 1964’s The X-Men #4, the Scarlet Witch and Quicksilver were said to be mutants, though their backstories have changed many times over the years. During 2015’s Uncanny Avengers (Vol. 2) #4, however, Wanda and Pietro Maximoff’s origins were retconned, as they were revealed to not be mutants at all, but actually the products of genetic experiments by the High Evolutionary. This allowed them to be introduced into the MCU’s Phase 2 as regular humans, albeit with superhuman abilities, but one powerful X-Men villain from Marvel Comics could explain their mysterious origins in the MCU.

Wanda & Pietro Maximoff Were Chosen By HYDRA For A Reason

Wanda and Pietro Maximoff’s MCU debuts confirmed that their abilities had been gifted to them through HYDRA experiments in Sokovia. WandaVision episode 8, “Previously On”, revealed that Wanda and Pietro Maximoff were exposed to the Mind Stone housed inside Loki’s scepter, which unlocked their powers: access to chaos magic for Wanda, and enhanced speed for Pietro. However, Wanda and Pietro, and HYDRA’s other test subjects, weren’t chosen at random, according to the Marvel-released The Wakanda Files book. This book revealed HYDRA chose to base themselves in Sokovia because its residents possessed “the appropriate genetic markers” for their so-called Miracles experiments.

Some have theorized that this could have been hinting at the existence of mutants in the MCU, and this theory picked up steam following Disney’s acquisition of 20th Century Fox in 2019, and the integration of mutants into the MCU. This may have been Marvel Studios’ way of retconning Olsen’s Scarlet Witch and Taylor-Johnson’s Quicksilver as mutants in the MCU. However, this doesn’t necessarily mean certain residents of Sokovia are mutants, as it’s also possible that one iconic X-Men villain from Marvel Comics may have been scheming and running experiments long before HYDRA set themselves up in their Sokovian stronghold.

Mister Sinister May Have Run Experiments On Sokovian Citizens

Mister Sinister is one of the X-Men’s most memorable antagonists in Marvel Comics, and one who could have had a hand in giving Wanda and Pietro Maximoff their abilities in the MCU. Mister Sinister’s Marvel Comics backstory reveals that he was born as Nathaniel Essex in Victorian London. As a young adult, Essex became interested in Charles Darwin’s research on evolution, and he became more obsessed with improving the human genome after losing his four-year-old son. After learning about mutant genetics, Essex worked alongside Apocalypse to experiment on mutants, and enhanced himself into an ageless being, dubbing himself Mister Sinister.

Mister Sinister was teased relentlessly in 20th Century Fox’s X-Men franchise, but never debuted in live-action. Marvel Studios could finally bring Sinister to life in the MCU, and connect him to the franchise’s past stories by having him be active in Sokovia decades ago. It’s possible that Sinister may have experimented on Sokovian citizens, evolving their genetic markers and perhaps even implanting superhuman abilities, which could explain why so many Sokovians had these markers when HYDRA came to town. This would explain one of the MCU’s oldest mysteries, and introduce Sinister as one of the MCU’s longest-running, albeit hidden, villains.

MCU’s Scarlet Witch & Quicksilver Aren’t Mutants, But Could Still Connect To The X-Men

Wanda and Pietro Maximoff are not mutants in the MCU, but having them be the product of Mister Sinister’s machinations and experiments in Sokovia could still connect them to the X-Men. Sinister himself isn’t a mutant in Marvel Comics, but became so obsessed with obtaining abilities that he enhanced himself using Celestial technology, and he went on to become one of the X-Men’s most iconic and long-running antagonists. Similarly, the Scarlet Witch and Quicksilver were involved with the X-Men for decades, so it would be great to tie these characters to the mutant team in the MCU’s upcoming X-Men reboot.

The Scarlet Witch and Quicksilver were the children of Magneto in Marvel Comics, prior to 2015’s retcon.

Mister Sinister can still keep his Marvel Comics backstory in the MCU, which will allow him to retain his British Victorian roots. He may have come to Sokovia for the same reason as HYDRA – the Eastern European nation was remote, and so his unusual experiments were unlikely to be noticed. If Sinister had experimented on Wanda and Pietro’s ancestors, his genetic edits would have passed down into the future superheroes. The twins were considered mutants in Marvel Comics for over five decades, so it would make sense for them to somehow be connected to the X-Men in the MCU.

Mister Sinister Is The Perfect Debut Villain For The MCU’s X-Men Team

Not much is yet known about Marvel Studios’ upcoming X-Men reboot, but Mister Sinister would perhaps make the perfect villain for their MCU debut. Nathaniel Essex’s existence was hinted at many times in 20th Century Fox’s X-Men franchise, but unfortunately never actually appeared in live-action. Mister Sinister is one of Marvel Comics’ most powerful and significant villains, so he deserves a live-action adaptation, and the MCU’s X-Men project would be the best place for this to happen. If this theory turns out to be true, Mister Sinister’s inclusion could also connect the X-Men to the wider world of the MCU.

While Nathaniel Essex’s Mister Sinister hasn’t made his live-action debut, the interpretation of the villain in Marvel Studios Animation’s X-Men ’97 series, a revival of X-Men: The Animated Series, proves he’d work perfectly in the MCU. X-Men ’97 episode 3, “Fire Made Flesh”, saw Mister Sinister unleash Madelyne Pryor on the X-Men, and he made a brilliant and persistent villain in the previous series. Mister Sinister’s terrifying nature in animation proves how effective he’d be in the MCU, and this would be even more powerful if Marvel Studios’ X-Men reboot connects him to the Scarlet Witch and Quicksilver’s incredible abilities.