As this site proves, I’m a huge fan of shared universes. Between Star Wars, Marvel, and DC Comics, I have found countless hours of entertainment. One of the biggest shared universes is the Arrowverse, named after the TV show Arrow, which started the timeline. The Arrowverse consists mostly of the shows Arrow, The Flash, and Legends of Tomorrow, though it also includes the 1-season run of Constantine and the short animated series, Vixen. Supergirl, on CBS, was another show that crossed over into the Arrowverse, but only in the form of an alternate dimension that the Flash was able to visit because he can do that.
Recently we’ve learned that Supergirl will leave CBS and shift over to the CW. Not long after that announcement, we learned that CW was planning a massive 4-way crossover between all of its shows. Crossovers have proven themselves in past (especially in comics) to be a huge boost to ratings/sales. The Marvel Cinematic Universe thrives on this idea, with films like The Avengers and Captain America: Civil War acting as massive crossover films. The Arrowverse has benefited with increased ratings for its Arrow/Flash crossovers, and events like Constantine’s appearance on Arrow. It therefore makes sense that more crossovers would be something DC is interested in arranging.
But here’s the part where I engage in a bit of informed speculation, based on what we know of the DC on TV. This is a combination of what I’d recommend for the Arrowverse combined with what I think is actually plausible.
Step 1: How CW will include Supergirl into the Arrowverse.
SPOILERS FOR THE ENDING OF THE FLASH SEASON 2
The ending of season 2 of The Flash teased a very important storyline: Flashpoint. In the show, Flash went back to the moment his mother was murdered and chose to save her. In the Flashpoint comics, the Flash also saved his mother in the past. However, this eventually led to an alternate universe where everything had changed. In his attempt to fix his mistakes, the Flash essentially merged several multiverse timelines into one. Not only will this make an interesting story for season 3 of The Flash but it also sounds like a good way to bring Supergirl into the same timeline.
Since Supergirl exists in an alternate dimension from any of the other CW shows, crossovers become complicated. Since the Flash can hop dimensions, he can enter her universe, but the possibility of other characters (like Arrow) joining Supergirl would require some creative (and far-fetched) storytelling. Currently the Arrowverse has no Superman, Supergirl, Martian Manhunter, or any other aliens living among them (that we know of). But if that rumored 4-way crossover is happening, it would be the perfect opportunity for a Flashpoint storyline to play out, merging the universes, and bringing Supergirl into the main continuity. This would make future crossovers interesting, and would also provide a great story for a crossover of that scale.
Step 2: The Man of Steel in the Arrowverse
Recent reports suggest that CW is currently casting for the part of Superman. While a part of me would like Smallville’s Tom Welling to return in the role, it’s much more likely that the Man of Steel will be played by a new actor. This is an interesting move for the Arrowverse. In the past, DC Comics has often hesitated to use its tent-pole characters, especially when there are films actively in production with those characters. While Superman did have Smallville back in the 2000s, creators have been slow to include him in Supergirl. But that seems to be changing since we will soon have two Supermen and two Flashes between the Arrowverse and the film universe. The doors are open for multiple versions of a character, and I expect we’ll see more of that in the future of the Arrowverse.
Step 3: Gotham and Batman in the Arrowverse
Speaking of tent-pole characters, Batman has not been seen on live-action television in decades. But we now have Gotham, which portrays a younger version of the character. The response to the show started as mixed, but critical reception of the show has improved through the second season. And yet we are still a long way from seeing this younger version of Bruce Wayne become Batman.
So far, Gotham has been its own thing, airing on a separate network from the rest of the Arrowverse, and taking place an undisclosed number of years in the past. While this may seem like it complicates potential inclusion in the Arrowverse timeline, it actually makes it easier. Let’s assume that Gotham is part of the Arrowverse. It would, by necessity, probably take place 10-20 years before the main timeline. But this is good, because it means that by the time Oliver Queen and Barry Allen don their masks, Bruce Wayne would be old enough to don his own cape and cowl.
So here’s what I’d do. First, let Gotham run its course over on Fox. I imagine this will take a few years. Second, acknowledge its existence in the Arrowverse by including future versions of the characters such as Jim Gordon or the Penguin, maybe even Batman himself (with an older actor of course). Legends of Tomorrow would also be a great venue for a crossover, since that show features time-travel, and could easily visit the world of Gotham. Third, once Gotham has been cancelled, create a new Batman-centric show on the CW. While this could simply be a show about Batman, the Bat-mythos is expansive enough that you could have a whole show focusing on the Bat-family, some of the villains, or any number of the many characters in the Bat-mythos. Since the CW is already crowded with other shows, this new Batman show would probably need to replace an existing show, such as Arrow. But the cast of Arrow could still continue to live on via crossovers in collective CW shows.
Step 4: Wonder Woman in the Arrowverse
Of course, if we have Superman and Batman, the Arrowverse would not be complete without Wonder Woman. In the current line-up of shows, the easiest way to include her would be on Legends of Tomorrow, however, I think she would be more suited for her own show, which could remain mostly isolated in the timeline, since that’s exactly how the Amazon warriors lived. It would also provide a good avenue to introduce the more mythological side of the DC Universe, something the Arrowverse hasn’t touched on much. Also, imagine how awesome a Hawkgirl/Supergirl/Wonder Woman crossover would be.
Step 5: Play around with the multiverse.
Between the Flash’s ability to travel the multiverse, and the cast of Legends of Tomorrow able to travel across time, DC has a lot of flexibility with what they can do with the Arrowverse. They could create alternate timelines, merge others, etc. Now many have complained about the fact that DC’s film and television storylines are not part of the same universe. Sharing a universe between film and television limit creativity for both, so this kind of makes sense.
However, with the multiverse as their excuse, the creative team of both the films and the television shows have an easy method for potential crossovers. At the very least, it could be possible to get a glimpse of the film universe in the television universe, or vice versa. An acknowledgement of their co-existence in the multiverse would be pretty cool, especially since the multiverse has always been a thing that DC Comics has embraced. And with Geoff Johns (who was heavily involved in the creation of the Arrowverse) taking over the creative side of DC Films, I think it’s entirely possible that a minor crossover could happen. This allows for cohesion, but also for each side to enjoy more creative freedom when developing their own little universe. The multiverse would also allow for connections to other universes, such as Smallville or other older DC television shows.
Step 6: Justice League?
The Justice Society of America was teased at the end of season 1 of Legends of Tomorrow, but that is not the same organization as the Justice League. If the Arrowverse included such characters like DC’s big three (Superman, Batman, and Wonder Woman), it would only make sense to have a justice league. However, I would not do this as a full show. Instead, I would bring all of the characters in a mid-season miniseries of roughly 8 episodes (similar to how Agent Carter aired during the mid-season break of Agents of S.H.I.E.L.D.). This would keep the CW network from getting even more cluttered, but would allow for some great storytelling in what is essentially a massive crossover. DC’s television shows have already included several core members of the Justice League (Flash, Superman, Martian Manhunter), so the possibility already exists. However, without Batman or Wonder Woman, the Justice League would not really be a good avenue to explore. So a lot will depend on those characters being introduced in the future of the Arrowverse canon.
This is all, of course, pure speculation. But assuming the Arrowverse continues for many years (which is known to happen on the CW), I expect the creators will eventually want to bring in some of these characters, and explore some of these storylines. The Arrowverse is already huge, and it will only get bigger. We can only hope!