Next week, The CW's beloved superheroes return with The Flash airing its Season 3 premiere on Tuesday, October 4, followed by the Arrow Season 4 premiere on Wednesday, October 5, the Supergirl Season 2 premiere on Monday, October 10 and the Legends of Tomorrow Season 2 debut on Thursday, October 13. The network has already announced a massive crossover that will include all four shows, and today we have a new video that brings Supergirl into the beloved "Superhero Fight Club" that was introduced last year. If that wasn't enough, we also have details on who all of these heroes are fighting, a new trailer for Arrow and set photos from Arrow's 100th episode, which will be part of this four-night crossover, which features a surprising inclusion.

Last year, The CW unveiled a video that featured stars from Arrow, The Flash and Legends of Tomorrow, dubbed Superhero Fight Club, where all of these heroes and their villainous counterparts would fight each other, on a secret floor of the Palmer Industries building. The video became quite popular with The CW fans, so this year, the network is bringing Supergirl into the mix, with a new trailer that starts off with Arrow (Stephen Amell) and The Flash (Grant Gustin) "kidnapping" Supergirl (Melissa Benoist), although she admits right off the bat that she let them abduct her.

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After she guesses that she was secretly kidnapped for this Superhero Fight Club, she gets introduced to a number of other heroes such as Atom (Brandon Routh), White Canary (Caity Lotz) and Firestorm (Franz Drameh). The facility itself was given quite the upgrade, to accommodate Supergirl's abilities, with the Superhero Fight Club 2.0 setup run by "Team Tech," Arrow's Felicity Smoak (Emily Bett Rickards) and The Flash's Cisco Ramon (Carlos Valdes). Since we don't get to see any actual fight club action, it's possible this may be the first in a series of Superhero Fight Club videos, possibly leading up to the four-night crossover.

Speaking of the crossover, The CW confirmed today that the episode will air in the late fall, and it will feature Arrow, The Flash, Legends of Tomorrow and Supergirl facing the DC Comics villains known as The Dominators. These villains are a sinister, technologically advanced alien race who view Earth's tendency to generate super-powered people as a sign that humans may essentially evolve to be genetically superior, leading to their decision to wipe out humanity. The Dominators' story was part of a three-issue comic crossover event dubbed Invasion, which was drawn by Spawn creator Todd McFarlane. Here's what executive producer Marc Guggenheim had to say about these villains in a statement.

"This year, for our mega Arrowverse crossover, we're taking inspiration from a DC crossover from the late 1980s known as Invasion!, which featured an alien race called the Dominators, who'd previously vexed the Legion of Super-Heroes. We're using cutting edge prosthetics and computer effects to achieve a feature film-quality look which is faithful to Invasion! artist Todd McFarlane's interpretation of the characters."

We also have a new trailer for Arrow Season 5, along with a slew of new set photos that star Stephen Amell has posted on Twitter. These images are from the production of Arrow's 100th episode, which appears to be a part of the four-night crossover, since some of these images feature Supergirl star Melissa Benoist, The Flash star Grant Gustin and Legends of Tomorrow stars Victor Garber, Franz Drameh and Caity Lotz. There is also a mysterious photo with Stephen Amell sharing a park bench with none other than Deathstroke in full costume. Take a look at all of the videos and photos below as we get closer to all of these superhero programs' new seasons on The CW.