The CW has been building its DC Comics shared universe since Barry Allen (Grant Gustin) was introduced on Arrow and spun off onto his own series with The Flash. Last year, The CW kicked off its second spinoff series, Legends of Tomorrow, comprised of new characters as well as those from Arrow and The Flash. Then, this past spring it was announced Supergirl - which had aired its first season on CBS - would be joining The CW for the show's second season. Previously, it had been confirmed that Kara Danvers (Melissa Benoist) exists on a different Earth than Barry when he accidentally traveled to National City as part of a Supergirl and The Flash crossover.

Now, with all four series on one network and established as existing in a multiverse, The CW is gearing up for a major crossover event this fall, followed by a two-episode team-up of Supergirl and The Flash that will include a musical element. To preview the network's superhero-heavy fall lineup, The CW released a new promo for all four DC Comics series.

The CW debuted a scene [above] from the full Superhero Fight Club 2.0 short - a followup to last year's Superhero Fight Club - that introduces Supergirl to the lineup of heroes. Also appearing in the scene are The Flash, Green Arrow (Stephen Amell), White Canary (Caity Lotz), Firestorm (Keiynan Lonsdale), and the Atom (Brandon Routh). The full Superhero Fight Club 2.0 short is available exclusively through The CW app, which is free to download.

The CW Legends of Tomorrow Arrow The Flash Supergirl

Superhero Fight Club 2.0 scene also features "Team Tech" - Cisco Ramon (Carlos Valdes) and Felicity Smoak (Emily Bett Rickards) - while the full-length short additionally includes Arrowverse players John Diggle (David Ramsey) and Hank Henshaw/J'onn J'onzz aka Martian Manhunter (David Harewood). Plus, the full Superhero Fight Club 2.0 features a return of one of The Flash's most fan-favorite villains - one that Team Tech would have needed to travel to Gorilla City to retrieve.

Of course, Superhero Fight Club 2.0 is simply a promo for the upcoming seasons of Supergirl, The Flash, Arrow, and Legends of Tomorrow respectively (as well as an offer of exclusive content to those who have downloaded The CW app). It doesn't necessarily offer any tease of what to expect from the seasons themselves - and doesn't even broach the subject of how The CW heroes abducted Supergirl from her Earth, though presumably it was through The Flash's technology.

That said, it's a fun bit of marketing that will likely get fans of the DC Comics television heroes excited for the official crossovers that will arrive during their respective seasons. Production has officially begun on the major crossover - as revealed by a photo of Supergirl and the Green Arrow - so more information about the four-show event will likely be arriving soon. In the meantime, fans can watch Superhero Fight Club 2.0.

Next: The CW DC Comics Crossover Villain Revealed

The Flash season 3 will premiere Tuesday October 4 at 8pm on The CW, Arrow season 5 will premiere in the same timeslot on Wednesday October 5, Supergirl season 2 on Monday October 10, and Legends of Tomorrow season 2 on Thursday October 13.

Source: The CW