Supergirl's Chyler Leigh on Alex's Relationship With Batwoman in The Flash: Armageddon

Tonight, the fourth and penultimate part of The Flash's "Armageddon" crossover will air on The CW, and in the episode, Alex Danvers (Supergirl's sister, played by Grey's Anatomy veteran Chyler Leigh) gets to share some screentime with Batwoman (Ryan Wilder). Given the ways this crossover seems to be positioned as a sequel to "Crisis on Infinite Earths," putting the two together feels like a nod to the relationship that they built between OG Batwoman Kate Kane (Ruby Rose) and Supergirl herself (Melissa Benoist) during that crossover. In "Armageddon," the timeline has been reconstructed in such a way that Eobard Thawne (Tom Cavanagh) is engaged to Iris West (Candice Patton), and a number of heroes in attendance at their rehearsal dinner didn't seem happy to see Barry Allen (Grant Gustin).

That will shift how the relationship between Alex and Ryan will be seen going forward. Still, it's an interesting chemistry the two bring to the screen, and it seems likely elements of the rewritten timeline will have "echoes" in the main line continuity at some point.

"I thought it was just a super cool way to show some really great representation for lesbian characters, and being able to honor that, and celebrate that, in a way where you see two women that are just kicking ass and they're owning who they are, and they know who they are," Leigh told ComicBook during a recent interview. "But Javicia is super cool. We had a really great time. We actually only worked one day together, just because her schedule was so intense; obviously she's also doing Batwoman. So it was great that she actually was able to come, and have the time that she did with us. She's just super cool, and she is wicked with the stunt stuff and everything. I don't want this to sound lame, but I was super impressed."

Ironically, since she appears in costume as Sentinel in the crossover, Leigh revealed that one of the biggest challenges was literally deciding how to present herself onscreen side by side with another hero she doesn't have an existing rapport with from her Supergirl years. 

"When you dive into these things, it's such a different way to act and perform ,that it took me a minute to get used to, for sure," Leigh admitted. "You just go, 'Okay, wait, so should I stand like this?' Or, 'Okay in this scene, are you crossing your arms and mine are hands in my hips? Let's make sure that we're not doing the same thing.' So you try to definitely make it your own, but also keep that classic comic book vibe to it."

In "Armageddon," a powerful alien threat arrives on Earth under mysterious circumstances and Barry (Grant Gustin), Iris (Candice Patton) and the rest of Team Flash are pushed to their limits in a desperate battle to save the world. But with time running out, and the fate of humanity at stake, Flash and his companions will also need to enlist the help of some old friends if the forces of good are to prevail.

The Flash airs Tuesdays at 8 p.m. ET/PT on The CW.