DCU's The Flash was rumored to include a Grant Gustin Flash movie cameo, mirroring Ezra Miller's appearance on the Arrowverse Crisis on Infinite Earths crossover. Since 2014, The CW's The Flash has been one of the biggest DC TV shows of all time. After his two-episode arc on Arrow, Gustin went on to star in his own series which has been one of the Arrowverse's flagship shows for close to seven years. The spinoff series not only introduced superpowers into the franchise, but The Flash was crucial in seeding the idea for Crisis on Infinite Earths, which was the last major crossover the Arrowverse did in 2019.

After appearing in Batman v Superman: Dawn of Justice, Suicide Squad, and Zack Snyder's Justice League, Ezra Miller's The Flash solo film is finally happening, following years of development hell. The DCU movie will see Flash explore the Multiverse — and according to rumors, Gustin's Arrowverse Flash could be involved in some capacity. The theories suggested Gustin could make a cameo appearance in The Flash movie, following Miller's big moment in Crisis on Infinite Earths, where they shared the screen together. However, with James Gunn now in charge and changing the DCU and The CW Flash ending, many of the old rumors could no longer be accurate.

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Gustin & Miller's Flash Did The "Impossible"

Ezra Miller and Grant Gustin as Flash

A Grant Gustin Flash movie cameo has been speculated over for years. In the early days of the DCU and the Arrowverse, many wondered whether Warner Bros. could connect the two universes. It was eventually confirmed that Arrowverse shows would not connect to the DCU. As the two separate arms of DC live-action developed into distinct franchises, many assumed it would be impossible because of "confusing" continuities or different tones. No one thought the Arrowverse and DCU would have anything to do with each other, whether it was people in the industry or fandom. Most decided it would never be possible. But Crisis on Infinite Earths changed everything.

Warner Bros. turned to the Arrowverse team to have Miller's Flash appear in a cameo for the Crisis on Infinite Earths crossover. The moment Miller and Gustin's Flashes came together was a massive shock for Arrowverse and DCU viewers. While it was a short scene, their exchange was historical, as their characters did "the impossible." This marked the first time that the Arrowverse had any character from the DCU appear in The CW universe. Out of all the DC cameos in Crisis of Infinite Earths, Miller's scene with Gustin's Flash is still the most talked-about surprise. Their moment broke a barrier between the DCU and DC TV, making multiverse crossovers possible — especially a Grant Gustin The Flash movie cameo.

Gustin And Miller Meeting In-Universe Helped Ease Fanbase Feuds

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Having Miller's Flash appear in Crisis on Infinite Earths also helped silence a long-time online dispute. When Miller's casting happened a week after The Flash's premiere in 2014, there was a massive negative reception, with fans feeling Warner Bros. was stealing the thunder from the hero's DC TV counterpart. However, throughout the years, there has been a ridiculous online feud between the respective fandoms of Gustin and Miller's respective versions of The Flash. There have been online arguments that Gustin's Barry should have been cast in the movie instead of Miller. A Grant Gustin Flash movie cameo could pay it back.

On the other hand, there have also been those arguing that casting Miller fixed the problems with The CW iteration. Several fans felt Gustin's Flash is either too good to appear in the film, or the Arrowverse iteration is not worthy of the big screen. Fandoms tried to pit Miller and Gustin's Flashes against each other in a negative, toxic way, while the actors only showed support for one another. Not only did their Crisis on Infinite Earths moment allow online feuds to be put to rest, but it also set a precedent for a Grant Gustin DCU cameo in The Flash movie.

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Gustin's Flash Is The Most Logical DC Multiverse Character To Cameo In The Flash Movie

Grant Gustin Flash DCEU Flash concept art

The Flash movie already lined up a pretty big cast, especially as it pertains to the DC Multiverse. Ben Affleck's Batman will be back, and the film is also re-introducing Michael Keaton's Batman as part of the movie's Multiverse storyline. Since The Flash movie is indeed featuring characters from multiple live-action DC continuities, a Grant Gustin Flash movie cameo is the most logical DC Multiverse crossover. For decades, exploring the Multiverse has been part of The Flash's DNA, whether that is in the comics, other media adaptations, or the ongoing TV show.

One of Flash's most iconic storylines in the comics is Flash of Two Worlds, where Jay Garrick and Barry come together for the very first time. Many might wonder what the point is of Gustin's Flash showing up in the film, even for just a cameo, given they've already done that in the Arrowverse — but big as it is to see DCU's Supergirl debut and an alternative Batman return, it makes way more sense for a Multiverse Flash to show up in a DCU movie than the Girl of Steel and Dark Knight. It would just be better if this was in addition to a Barry from another Earth.

If Gustin is indeed making a cameo in The Flash film, what that will actually look like remains to be seen. It could be that the Crisis on Infinite Earths moment is revisited from the perspective of Miller's Barry Allen. Only time will tell, but if Gustin is reuniting with Miller in The Flash movie, it will not only have a huge impact on the DC live-action Multiverse, but it will be fitting for the Scarlet Speedster's cinematic adventure. One thing that is certain — since the two multiverse-hopping heroes have met once already, it would almost seem strange if Grant Gustin doesn't appear.

There's Been No Confirmation Of A Grant Gustin Flash Movie Cameo

The Flash Movie Different Lightning Colors.

There is no confirmation that a Grant Gustin Flash movie cameo is coming at all. With James Gunn taking over the DCU he has brought with him a total shake-up of the upcoming slate, and very little from the former DCEU looks like it will move forward outside TV shows focusing on Amanda Waller and Peacemaker.

With Flash ending on The CW, and Ezra Miller's The Flash movie possibly being the final installment in the former cinematic universe, there is no payoff to Gustin appearing beyond pleasing fans. It also doesn't make sense from what's been seen of The Flash movie's narrative. Grant Gustin showing up in The Flash would definitely be an interesting moment, but since the rumors are unconfirmed, there's little concrete reason to expect the Arrowverse Barry Allen to make a DCU appearance.

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