Plenty of familiar faces from across the Arrowverse return for The Flash's crossover event, "Armageddon." Among several returning heroes is Alex Danvers (Chyler Leigh), aka her crimefighting alter-ego Sentinel. Alex's appearance on The Flash allowed Leigh to find a level of closure with the character without the emotional weight that came with her initial goodbye to the role in the Supergirl series finale. While Barry Allen finds himself in an unsettling vision of the Arrowverse, Alex remains steadfast in her commitments to help Team Flash.

In an exclusive interview with CBR, Leigh reflected on how she wanted Alex Danvers to appear in "Armageddon." She also shared how her return helped her process Supergirl's conclusion and expressed her hopes in Alex resurfacing someday in the Arrowverse's future.

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The Flash -- "Armageddon, Part 4" -- Image Number: FLA804a_0401r.jpg -- Pictured (L-R): Chyler Leigh as Sentinel, Kayla Compton as Allegra Garcia, Brandon McKnight as Chester P. Runk, Candice Patton as Iris West-Allen, Javicia Leslie as Ryan Wilder/Batwoman, Osric Chau as Ryan Choi, Andres Soto as Marcus and Danielle Nicolet as Cecile Horton -- Photo: Katie Yu/The CW -- © 2021 The CW Network, LLC. All Rights Reserved

Logistically, how quick a turnaround was it to wrap on Supergirl and then return as Alex Danvers for The Flash?

Chyler Leigh: It was a few weeks. We wrapped Supergirl on Aug. 6, and then around mid-September, I flew back to Canada to prep and get ready for The Flash. It was only a few weeks.

How did that affect your processing wrapping Supergirl? You already had the big emotional sendoff with Melissa Benoist, David Harewood, and Azie Tesfai at that point.

It was trippy, I'll be honest. It was a really tough season last year, just knowing it was the last and getting that word a little bit late and with COVID. Everything made the last season a little bit funky and I felt like it took away a lot of the experience we could've had, and then it being done -- it was really emotional. Azie and I kept joking that since David had officiated Chris [Wood] and Melissa's wedding, he officiated our wedding [in the Supergirl series finale] so are we married? [laughs]

It definitely wore me out. I was planning to hang there before I even knew The Flash was happening because we still have a house up there that we're renting for now. I was going to hang there for a minute but my husband was like, "Babe, just for your mental health, I think we should go home for a bit. Let's reset and get you resting for a minute and we'll go from there."

A couple days before I wrapped on Supergirl, they called me about The Flash. After getting a bit of a reset, I thought it would be good because it gives me a chance to really be Alex again, be the Sentinel side of Alex, but still the heart and everything that I love about her so much that was there. I feel like I got a second chance to go out in a way that wasn't as emotional where I could just stand alone and feel like this was a cool way to wrap it up.

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One of the throughlines thematically on Supergirl was the truth and the truth about finding love, which you deliver in scenes here on The Flash. How was it embodying those themes and imparting that wisdom?

I was so grateful! It was funny because originally Eric [Wallace], the showrunner, hadn't seen the last couple episodes of Supergirl so he was going in a little bit of a different direction which was really cool but it had Alex a bit more down-in-dumps and a little bit more cynical towards love. I called him up saying we should talk and told him this is where we were at -- with a huge, emotional wedding at the end [of Supergirl]. He was like, "Oh my gosh!" We had this really great conversation about it.

supergirl alex and kelly's wedding

It really just inspired him and he went, "This is so much better than I originally thought and I'm really proud because it gives Alex a chance to be a beacon of hope and love in a way that really respects who Alex is and her journey and also can come across as someone who is really encouraging for Allegra and Chester." It just gave a great sense for her to come in a little bit in that mama bear role and impart all that she's gone through. To give that wisdom and tough love was fun. I always love being tough Alex: when I get to yell at people, it's awesome. [laughs]

Speaking of badass action Alex, we had just started to see Alex really come into her own as a superhero towards the end of Supergirl. How it is putting the Sentinel outfit back on and mixing it up with the characters on The Flash?

I'll be very honest, I'm just glad it still fit because I rested and went through a lot of emotional eating. [laughs] I thought, "This definitely tightened up in the archives, that's what happens?" [laughs] The last day on Supergirl when we did the huge showdown with all of us in our super-suits, you've got twenty people lined up in leather and you're always laughing because it's great but we look so silly. [laughs] None of us processed the fact that this was going to be the last time we were in those suits, so even that was super emotional because it was my goodbye to Sentinel and it came out of nowhere -- at least that's how it felt at the time. It was like, "This is it, don't walk away. Everybody needs to get together for a picture!"

It was emotional and really sad giving back my costume and hanging it back up in my trailer like I was letting her go. To have the chance to put that suit back on, I walked on to set and everybody went, "We think you have the coolest suit!" I was like, "Damn right, I do!" [laughs] It was pretty cool.

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The other familiar face behind the camera is Chad Lowe, who helmed a couple of episodes of Supergirl. How was it having him as a director on this episode?

I absolutely adore Chad!

He is so sweet and he's got such great vision but it's always so hard to do any of that crossover stuff. From an acting standpoint, him being a director on Supergirl, and to see him here, I was super relieved. Some of the actors on The Flash I've worked with before, and you never really know, walking on to someone else's set, what the vibe is. We worked really hard on Supergirl to maintain a really respectful, efficient, kind and fun set because we're all working together so long and just as hard -- so don't be an asshole. [laughs] I was really glad because the crew is just so fantastic over there and all the actors that I got to work with, we had so much fun. I felt like it was really nice transition over there to spend that time. Chad was just another lovely face to see, for sure.

Unlike Arrow, which closed the book definitively on Oliver Queen -- may he rest in peace -- you and the Supergirl cast are still kicking. Would you be open to returning as Alex again?

In a heartbeat!

I would do it all over again and I'm still rooting for a Kelly and Alex spinoff. I don't know, I'm just saying rooting for it... You didn't see Kelly and Alex ride off into the sunset but hop onto their bikes to go save other people, Esme would love that. I'd love to throw that around and get that trending. [laughs] I would honestly really do it in a heartbeat. I love Alex and everything that I got to build with her and how I grew as a person and the love that I have for my family is love that I was able to embody through her. I'd absolutely love to put that suit back on. I'd just have to shed a few pounds again. I kind of went back on an eating kick. [laughs]

The Flash airs Tuesdays at 8 pm ET/PT on The CW, with new episodes available to stream the following day on The CW App.

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