Avengers 4 is the perfect chance for Marvel to bring a much-loved character back from the dead - it's time for Quicksilver to fight alongside the Avengers once again. Aaron Taylor-Johnson's version of the super-speedster was introduced, and quickly killed off, in 2015's Avengers: Age of Ultron. In contrast, Fox has been developing their own version of Quicksilver - played by Evan Peters - since 2014's X-Men: Days of Future Past, and the Fox films have demonstrated rather well just how powerful a super-speedster can be.

On the rare occasion when a Marvel Cinematic Universe movie kills off a hero, they usually come back - just look at Phil Coulson and Black Panther. The cliffhanger ending of Avengers: Infinity War is the biggest "fake death" sequence to date, since several of the heroes who turned to dust are confirmed to return in their own sequels set after the events of Avengers 4. To date, Quicksilver's death is one of the few that has stuck. But should it stick? Will Marvel really lose anything if they bring Quicksilver back from the dead - and what could they gain?

Avengers 4 Will Revisit Major Events

Set photos from Avengers 4 have clearly implied that the film involves some sort of time travel. A number of set photos have shown scenes during the Battle of New York, with Earth's Mightiest Heroes wearing their 2012 costumes. Thor has been spotted with his trademark flowing locks, Steve Rogers has been seen clad in his "old-fashioned" Avengers outfit, and there have even been images of the aftermath - with Loki being led away in chains. Surprisingly, though, these photos have also shown Ant-Man stood alongside the Avengers. There definitely seems to be an element of time-travel involved in the film, with both Ant-Man and an older Tony Stark traveling back to the past. It's not yet clear why, or even if any of the other Avengers of the present-day join them. But if they're revisiting the Battle of New York, there's no reason the heroes couldn't also intervene in other major Marvel events.

It's hard to get much more "major" than Avengers: Age of Ultron. The second Avengers movie saw the destruction of Sokovia when Ultron attempted to initiate an extinction-level event. The Avengers defeated Ultron, but at a terrible cost in terms of both lives lost and economic hardship to Sokovia's survivors. It's no coincidence the MCU's version of the Super-Human Registration Act is known as the "Sokovia Accords."

It seems likely that Ant-Man and Stark revisit the Battle of New York because there are Infinity Stones present: the Mind Stone and the Space Stone. The Mind Stone is also heavily involved in the events of Age of Ultron; Stark's experiments with it actually created Ultron in the first place, and it wound up embedded within Vision's forehead. So if the heroes are time-traveling in order to interact with Infinity Stones, Sokovia would be a logical place for them to go as well.

Aaron Taylor-Johnson Reportedly Spotted on Set

Avengers 4 seems to involve the return of a number of characters who have been dead for quite some time. There have been constant rumors that Frank Grillo has been on set, even though his character Crossbones was killed off spectacularly in Captain America: Civil War. Maximillio Hernandez, a.k.a. Jasper Sitwell was also in Atlanta during filming. This is probably related to the time-travel aspect of the plot; Sitwell, for example, played a key role in S.H.I.E.L.D.'s cleanup of New York after the Chitauri invasion, so his inclusion would make sense.

Fitting with this, in November last year the Daily Express - a British tabloid - claimed that Taylor-Johnson was in Atlanta on the set of Avengers 4. More recently, the Express has claimed he's returned there, with the film presumably undergoing additional photography. It's important to note that none of these accounts have been substantiated, so they should be treated with a certain degree of care. It's actually not even confirmed that Marvel is conducting additional photography on Avengers 4 right now; while reshoots are expected, Chris Evans told the New York Times that they'd be later this year.

So this one needs to be treated with a certain degree of caution. In reality, we have a limited number of unsubstantiated claims that Aaron Taylor-Johnson is on the set of Avengers 4. The probable time-travel element does mean it's possible, but right now the evidence is sparse. Still, it raises an interesting question; should he return to the MCU?

Page 2: Should Marvel Resurrect Quicksilver?

Quicksilver Was Underused in Age of Ultron

Quicksilver and his sister, Scarlet Witch, were introduced as villains in Avengers: Age of Ultron, but Quicksilver didn't really make a mark on the film. The real threat to the Avengers was Scarlet Witch, who used her telepathy to influence the Avengers. All Quicksilver really did in Age of Ultron was develop an amusing rivalry with Hawkeye, and ultimately die saving the Avenger's life. That death actually seems to have been forgotten by the MCU; no other Marvel film has even name-dropped Quicksilver, despite the fact Scarlet Witch played a major role in both Captain America: Civil War and Avengers: Infinity War. The only fallout we've seen is Hawkeye returning from retirement to help Team Cap in Civil War, because he felt he owed Quicksilver's sister a debt.

Although Taylor-Johnson was signed up on a multi-picture deal with Marvel, Joss Whedon always planned to kill Quicksilver off. In an interview with Comic Book, Whedon revealed that he told Taylor-Johnson this intention the very first time they met. Whedon's plan throughout the entire film was to leave viewers convinced Hawkeye was going to die, in order to subvert it at the last second and have Quicksilver die saving his life. While it worked in the context of the film, and it made narrative sense, it was also a shocking waste of a classic member of the Avengers.

Quicksilver was originally introduced as an X-Men villain (which is why Fox share the rights to the character), but he first joined the Avengers in 1965's Avengers #16. In the comics, the arrogant and brash speedster was one of the second generation of the Avengers, operating under Captain America's leadership. He famously added a complication to his sister's relationship with Vision, disapproving of it, but ultimately giving it his blessing to their marriage regardless. He's played a pivotal role in several Avengers stories, right up to this year's Avengers: No Surrender arc, which has launched Quicksilver's latest miniseries. As any comic book reader can attest, there is so much more to Quicksilver than this. It's true that Fox has made prodigious use of their version of Quicksilver in the X-Men films, but frankly Evan Peters's version shares the powerset and nothing more. Quicksilver deserves better.

Quicksilver Could Team Up With Scarlet Witch In Phase 4

The dynamic between Quicksilver and Scarlet Witch is the stuff of comic book legend, and it's a real shame we've not had chance to see it realized on the big screen. As writer Peter David has explained it, Quicksilver's mind processes information at the same speed his body moves. That means he lives in a constant state of frustration, waiting for the rest of the world to catch up to him. As a result, Pietro is extremely harsh and judgmental; once he's made up his mind about a person or situation, it's difficult to change it.

In contrast, Scarlet Witch tends to be an optimistic, seeing the best in people rather than the worst. Where her brother is quick to judge, she will always take time to think; where her brother will dismiss others as irrelevant, she cares deeply. Quicksilver loves his sister deeply, and is constantly frustrated at the decisions she makes, but there's a strange sense in which he knows she is the better person. Pietro's best moments are the ones where Wanda has acted as his anchor, holding the super-speedster firm to what is right.

If Marvel do use time-travel to bring Quicksilver back from the dead, they'd be able to exploit this fantastic dynamic as part of their post-Phase 3 movies. It's already known that Taylor-Johnson signed up for a multi-picture deal with Marvel, and there's no evidence Olsen's contract is coming to an end either, so the two would be able to interact in future Marvel movies. That wonderful dynamic could finally be explored on the big screen, just as it deserves to be.

Right now, the evidence is sparse, but it's possible Quicksilver will be returning to the MCU. If he does, it would be a smart move on Marvel's part, allowing them to develop a character who has frankly been underused in the MCU to date.

More: Infinity War 'Part 1' Was Marvel’s Best Trick - But 'Part 2' Poses A Problem

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