The Flash seems to be looking to familiar faces in of the casting choices for the DCEU film. While Ezra Miller's take on the speedster has been well received so far, the character has yet to have a spin-off film set in the same universe.
The creative team behind the movie seems to be discussing Flashpoint as a potential narrative option to move forward with. This means that there will be some time traveling and reality-bending events which could allow Barry Allen to explore the multiverse a little more. If the multiverse opens up further then there's a possibility other characters could appear from various properties!
Batman
There have already been rumors circulating that perhaps Michael Keaton's take on the dark knight may be returning to the big screen. This will be the second time that the Flash will have teamed up with a Batman.
Since this could involve the multiverse it means that Keaton's Bruce Wayne may be able to take on a mentor role to Barry Allen. He will have far more experience and the two could have a really compelling dynamic together.
The Flash
While it's obvious that the scarlet speedster will be a part of the Flash film there's plenty of other versions of the character from across the multiverse. The most notable version can be found on the CW.
The Arrowverse portrayal of Barry Allen has been a fan favorite version for some time. Not only this, but Ezra Miller's Flash has also actually crossed over with Grant Gustin; so why can't it happen again in the future?
Superman
While Crisis On Infinite Earths brought together some of the world's fastest men, it also Superman Returns. Brandon Routh had already been working in the Arrowverse as Atom.
However, his version of Superman also made a few appearances across the series and was confirmed to still exist at the end of the crossover. Perhaps he could jump to yet another Earth and appear alongside the crimson comet.
Reverse-Flash
The Reverse-Flash is without a doubt the worst villain in the Flash's rogues gallery. He is completely despicable in every way and really the motivator behind Barry wanting to create Flashpoint. It was after all Eobard Thawne's killing of Barry's mother that made him want to rewrite time.
This has already happened in the Arrowverse, so why not bring the same version of Reverse-Flash into the DCEU and have him continue to haunt the days of Barry Allen in every reality.
Crimson Comet
The Crimson Comet is a name that has been used to describe the other versions of the Flash on different Earths. For instance, John Wesley Shipp jumped into the role of Jay Garrick for the Arrowverse.
It would be great to see the original Flash actor back, this time for the DCEU, as the Crimson Comet. Of course, it wouldn't be right unless he brought with him his trademark winged helmet.
The Trickster
The Trickster has been one of the villains that were carried over between various multiverses. Mark Hamill has portrayed multiple versions of this villain on different Earths.
It would be fitting for the character to return again, with Mark Hamill in the role, in order to pay homage to all of his past appearances. Hamill has given a lot to the DC Universe, especially with his take on the Joker, so this is a perfect way to recognize that.
Impulse
On the popular show Smallville, Bart Allen was the resident speedster. The character quickly picked up his lightning-fast abilities and garnered the nickname Impulse.
The multiverse has shifted a lot thanks to the interference of the Anti-Monitor. There may still be a variation of that Earth out there, which could include Impulse as another member of the Allen family.
Brainiac
Brainiac has been a threat in multiple realities. His ancestor Brainiac 5 has been both an ally and enemy to Supergirl and her friends and the main character himself has terrorized the planet of Krypton.
There's a storm brewing in the multiverse and the DCEU could take advantage of that. Originally Darkseid was to be the big bad of the universe, but perhaps the collector of worlds Brainiac would be a far better option.
Iris West
Iris West has been a ing character to many iterations of the scarlet speedster. She's a huge part of Barry's story and it would seem odd not to have her included in this film in some way.
Rather than giving Ezra Miller his own version of the character though, it might be appropriate to show him the life he could have lived, by using the Arrowverse version of Iris West as an example.
Supergirl
The girl of steel is great friends with the Flash in the comics and in the Arrowverse. Much like Bruce Wayne could serve in a mentor role, perhaps so too can the film version of Supergirl.
Helen Slater portrayed the role originally and perhaps she would be a great addition to the story. Helen has since portrayed Eliza Danvers, Supergirl's mom, but perhaps there's one more chance for her to don the iconic S.
