The MCU's Quicksilver could be replaced - with the one from Fox's X-Men films. In the comics, Pietro Maximoff is one of the most important - albeit morally questionable - members of the Avengers. He was one of "Cap's Kooky Quartet," the second generation of Avengers, serving alongside Captain America, Hawkeye, and his sister Scarlet Witch. Like his sister, Quicksilver generally treads the line between the Avengers and X-Men franchises; for most of his history he's been considered a mutant and has served as a member of several X-Men splinter teams.

This resulted in a curious legal wrinkle for Quicksilver, because contractually, the movie rights for the super-speedster were shared between Marvel Studios and 20th Century Fox. Both studios had the right to use the character, although Marvel's version couldn't be a mutant or related to Magneto. It didn't take long for the potential issue to become a reality; Joss Whedon was already at work on introducing Quicksilver in Avengers: Age of Ultron when Fox switched gears for X-Men: Days of Future Past, replacing a planned Juggernaut appearance with their own version of Pietro. Fortunately, any conflict was swiftly averted, because Marvel chose to kill off their Quicksilver, while Fox never advanced any plans to introduce his sister Scarlet Witch.

Related: All The X-Men Movies In Chronological Order

All these problems are now resolved. Disney purchased the bulk of Fox's film and TV empire, and as a result all the X-Men film rights returned to Marvel. The main X-Men franchise has been wound down, ending with a whimper rather than a bang in X-Men: Dark Phoenix. But the last legacy of all this is a major gap in the Avengers lineup.

The MCU Is Missing Its Quicksilver

Pietro and Wanda Maximoff on a street in Sokovia in Avengers: Age Of Ultron.

The MCU's Quicksilver, played by Aaron Taylor-Johnson, was technically introduced in the post-credits scene of Captain America: The Winter Soldier. Unlike his comic book equivalent, Marvel's Quicksilver gained his powers as a result of Hydra experiments with the Mind Stone. He and his sister Scarlet Witch initially worked for Hydra, believing the Avengers a threat to their home nation of Sokovia. Unfortunately, where Scarlet Witch became an established character in the MCU, Quicksilver was swiftly killed off. This was Whedon's call, because he knew he'd set up viewers to believe he was going to kill off Hawkeye instead. Whedon felt it was disingenuous to make what he considered a war movie without any sacrifice, and he liked the idea of having Quicksilver - who Hawkeye genuinely hated - sacrifice himself for Clint. To Whedon's surprise, Marvel execs didn't push back at all.

They may have realized they were caught in a Quicksilver competition they couldn't win. X-Men: Days of Future Past released in 2014, and it introduced its own Quicksilver. Evan Peter's portrayal was tremendous, and Fox invested a lot of time and money in realizing his super-speed. They used high-speed cameras shooting at 3,000 frames a second, which means something that happens in the blink of an eye takes 15 seconds; camera rigs were moving at up to 90 mph. There was no way Marvel was going to match this, not least because CEO Ike Perlmutter - who called the shots back then - would have objected to the cost. Making matters worse, X-Men: Days of Future Past came out first, meaning the MCU's Quicksilver was inevitably going to be held to too high a standard. Given this context, it's no surprise Marvel simply shrugged and allowed Whedon to kill off Aaron Taylor-Johnson's Quicksilver.

While this decision made sense at the time, it leaves a gaping hole in the MCU's Avengers. Super-speed is one of the most entertaining powers when realized well, as demonstrated by both the X-Men films and The Flash on the small screen. But the ability is quite rare in Marvel comics, with Quicksilver easily serving as the most important super-speedster. Marvel would be wise to consider bringing Quicksilver back.

Related: How Marvel Phase 4 Is Already Incorporating X-Men Into The MCU

Avengers: No Surrender Hints How Quicksilver Could Enter The MCU

Quicksilver Avengers No Surrender

In a surprising twist, there have been recent reports Evan Peters is due to appear in the MCU in a mystery role. This has immediately fanned speculation Marvel is bringing Fox's popular iteration of Quicksilver over into the MCU, not least because Peters is reportedly appearing in WandaVision, a story focused on Scarlet Witch. It's a curious casting choice, and Marvel will have been well aware it would be jumped on as an X-Men connection. But is this just something of an overreaction?

There's evidence Marvel is preparing a retcon of Scarlet Witch's powers, revealing they operate in the same way as Doctor Strange's. As Marvel Studios president Kevin Feige put it in an interview back in 2016:

Her powers, she's never had any training, I'm talking about Scarlet Witch. She never had any training; she's figuring it out. Arguably, you could say that that's why her powers are much more chaotic and much more loose in the way that we showcased those light effects. In [Doctor Strange], some of what you might see today, even the cover of Entertainment Weekly, it's much tighter. It's all about focus. It's all about pulling energies from other dimensions in an organized and purposeful fashion, which is why they can do a lot more than she can in, at least, a much more precise way.

In the comics, Scarlet Witch is one of the most powerful sorceresses in the world, and has the ability to reshape reality itself. Thus she could indeed potentially pluck another version of Quicksilver from an alternate timeline. The comics' "Avengers: No Surrender" event helps, as it saw Quicksilver push his speed like never before, and he wound up trapped on another plane of existence; only Scarlet Witch was able to reach him. A similar story could allow Quicksilver to be brought into the MCU - initially unaware he'd abandoned his own reality - by merely running fast.

Quicksilver's 'Return' Would Be A Step Forward For Scarlet Witch

Scarlet Witch Avengers Age of Ultron

This wouldn't just incorporate Quicksilver into the MCU; it would also be an important part of Scarlet Witch's evolution as a character. Until now, Wanda Maximoff has been defined entirely by loss. She and her brother lost their family when they were just 10 years old, and they only survived because one bomb - sold by Stark Industries - didn't go off. This was a defining moment in Scarlet Witch's life, as the pain and fear she and Pietro experienced caused them to submit to Hydra experiments and then side with Ultron. They realized they had been manipulated, but teaming up with the Avengers led to Quicksilver's death, breaking Wanda's heart. The blows have kept coming ever since, with Scarlet Witch blaming herself for a tragedy in Captain America: Civil War, and then losing her lover Vision in Avengers: Infinity War. "You took everything from me," Scarlet Witch snarled at Thanos in Avengers: Endgame, her grief finally boiling over into anger.

The return of Quicksilver - even a different universe's Quicksilver - would be a key moment in Scarlet Witch's character arc. For the first time, Scarlet Witch's life would be defined by what she has gained rather than what she has lost. No matter this isn't the Quicksilver she grew up with; she would still have regained a brother after a fashion, and this could begin a process of healing. Such a restoration would be a wonderful step forward for Wanda, and hopefully it will fit well with the themes of WandaVision, which seems to be bringing back Vision as well.

More: Marvel’s New Phase 4 Slate: Every MCU Movie Release Date (2020-2022)

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