Melissa Benoist as Overgirl
Melissa Benoist said that playing Supergirl and Overgirl in this year’s Arrowverse crossover was a challenge. The CW

Melissa Benoist plays two different characters in this year’s four-way crossover event between “Arrow,” “The Flash,” “Supergirl,” and “Legends of Tomorrow.” Aside from playing Kara, aka the Girl of Steel, the actress also portrays Overgirl, the Nazi version of Supergirl, who appears to be one of the leaders of the Earth-X villains who crash Barry and Iris’ wedding.

During a press visit to the Vancouver set of “Supergirl,” Benoist admitted to a group of reporters that doing double duty in the crossover was a challenge. “I did play two characters. I did wear a very different outfit. There’s still a cape and my face is covered and she’s not so nice. It was pretty challenging,” the actress said (via ComicBook.com).

Although Benoist already played two different characters simultaneously in a couple of “Supergirl” episodes before, she said that portraying Supergirl and Overgirl in the crossover was a different experience. “I’ve had moments like [this] on this show [‘Supergirl’] with Bizarro and when Martian Manhunter (David Harewood) takes over Kara’s body, but this was entirely different. This was not even Red Kryptonite-isque. This was way worse.”

The “Glee” alum said that playing Supergirl and Overgirl was particularly difficult when they did motion control shots where she had to be in the scene with herself. “It’s more tedious than a traditional split screen,” Benoist said. “And essentially, you’re memorizing a whole scene, every line, every bit of dialogue and I didn’t anticipate how hard the transition would be to go from lightness to darkness. [It’s] a fun challenge.”

As seen in promo clips and photos for the crossover, Kara attends Barry (Grant Gustin) and Iris’ (Candice Patton) wedding with her adoptive sister Alex (Chyler Leigh). “It is very much a duke-it-out, like, ‘We’re here together. We’re in this,’” Leigh said (via Comic Book Resources) of what fans can expect from Kara and Alex in the crossover. “At certain moments, we’re fighting for each other, fighting to get to each other and fighting together. You really get to see a lot of sides of everybody, and sides that you wouldn’t expect.”

The crossover, titled “Crisis on Earth-X,” airs across two nights. It begins with “Supergirl” and “Arrow” on Monday, Nov. 27 at 8 p.m. EST, and ends with “The Flash” and “Legends of Tomorrow” on Tuesday, Nov. 28 at 8 p.m. on The CW.