Crisis on Infinite Earths became the biggest crossover event of all time for the Arrowverse as The CW’s DC TV franchise was forever changed through the 5-part event. After having spent several seasons of teasing and setting up DC TV’s adaptation of the famous storyline, everything has now changed. With the creation of Earth-Prime as well as a reboot of the Multiverse, it remains to be seen what the next set of crossovers will do.
With the amount of classic DC storylines that could be adapted or inspired by the small-screen, there’s a lot of potential for different kinds of crossovers.
Titans Tomorrow
Even though the Teen Titans haven’t been introduced properly in the Arrowverse, Titans do officially exist within the franchise’s overall Multiverse. Being set now on Earth-9, while it might be tricky to suddenly pull those versions of the Titans into an Arrowverse crossover, there’s a storyline that could still bring in those actors, but as alternative versions.
Titans Tomorrow focuses on an alternative timeline where the Titans have become violent versions of themselves. Having the cast of the DC Universe get brought in for a crossover using that storyline wouldn’t conflict with the plot of the Earth-9 version. However, if done right, a crossover event between the heroes of Earth-Prime and Earth-9 could work if the Arrowverse heroes get to know them before seeing their potentially future evil versions. It would be a solid combination of heroes of different worlds meeting for the first time as well as involving time travel.
The Death and Return of Superman
With the upcoming spinoff Superman & Lois, a crossover centered a Man of Steel story is inevitable in the future. While this is most likely better to be used in a few seasons, The Death and Return of Superman would be a solid 5 or 6-part event. If it’s done in a few years from now when the new version of the Arrowverse has been able to settle in post-Crisis, it has the potential to be a success.
Justice League: Origins
Even though the team (that is pretty much known as the Justice League, unofficially) has already come together, Justice League: Origins is still something that can be pulled off. Despite being the big storyline that brought the league together when the New 52 began, it was also the first time they faced the villainous Darkseid.
As the league is still finding itself post-Crisis, Darkseid is the biggest threat out there after the Anti-Monitor. The arrival of Darkseid could be the crossover where the team officially becomes known as the Justice League to the rest of the world.
Flashpoint
Despite the fact that The Flash already did Flashpoint in season 3, it was a lite version of the game-changing storyline. Not only did it exclude the rest of the Arrowverse, but the story only lasted for one episode before Barry reset the timeline. With Crisis having rebooted the universe, there is the chance now to do a more accurate take on Flashpoint.
It would probably have to exclude the New 52 factor of it all as Crisis has essentially already accomplished that. However, seeing an alternative reality of the Arrowverse heroes similarly to the book would be compelling. The only problem is that having to see Nora Allen be saved and then murdered again might be overdoing it.
Nights of the Owl
As Batwoman is continuing to settle in, a crossover having Kate more in the front and center has to happen at some point. One of the biggest DC storylines in recent years is Nights of the Owl featuring the Court of Owls as the primary antagonist. With Bruce Wayne currently MIA, telling the story from Kate’s POV would be intriguing as well as seeing how her fellow heroes tackle the villainous group.
Blackest Night
With the tease of Diggle beginning his Green Lantern adventures in the Arrow series finale, could a Green Lantern-themed crossover work? Even though it will air on HBO Max, the Green Lantern series was established to exist within the Arrowverse’s new Multiverse on Earth-12.
The best Green Lantern story would be Blackest Night that features the gruesome return of dead characters. The biggest Arrowverse character to come back through a crossover like this would be Oliver as it'd affect everyone. Being forced to go up against the man that literally created a new universe would make for one powerful crossover.
Crisis on Earth-1/Crisis On Earth-2
The DC Universe has had more than just one Crisis. With the arrival of Stargirl, a mini-Crisis crossover is possible. Given that Stargirl was established to exist on a reimagined Earth-2, the Crisis on Earth-1/Crisis on Earth-2 would be an appropriate crossover. Even though the writers would have to take liberties with the original story, having a crossover where The CW’s Justice League finally meets the Justice Society would be a big deal. This could also be where Earth-Prime starts discovering the new Multiverse.
Kingdom Come
With Brandon Routh reprising the role of Superman in the last crossover, his return came with a tease to one of the most iconic storylines in DC: Kingdom Come. While his Superman was brought back post-Crisis on Earth-96, the story could still go anywhere on his Earth. Adapting a version of Kingdom Come that allows Routh to come back could be done in two ways. Either the Earth-Prime heroes go to Earth-96 to deal with their future doppelgangers or the crossover takes place entirely on Earth-96. This could make the storytelling a bit easier by simply following the Earth-96 versions of heroes like Supergirl, Flash, Black Lightning, Batwoman and more. It would give the actors a chance to do something different without having the burden to play two characters each in the crossover.
Forever Evil
As the Multiverse got re-structured, so did Earth-3 that is most known as the home of the Crime Syndicate of America in the comics. One of their biggest storylines in recent years is Forever Evil where all three Justice League teams are dead and the DC villains get a bigger spotlight. The Arrowverse could easily do its own spin on Forever Evil as it would finally be able to bring in the Crime Syndicate at last.
JLA: Tower of Babel
Despite Batman still being missing, his inevitable return could perhaps be done through Mark Waid’s JLA: Tower of Babel. The plot features the league being defeated by Ra’s al Ghul after he steals Batman’s secret records about how to defeat each hero. This became a defining story for the Dark Knight as it was seen as a major act of betrayal to the league. While it’s a long shot, this storyline could still happen with a new twist of why Batman has been missing for years: he's been traveling around the world to document every superhero and how to defeat them if they were ever to turn on humanity.