'Supergirl' Boss Teases Girl Power And The Man Of Steel In Two-Part Finale

Warning: This article contains spoilers for the season finale of Supergirl.

Supergirl turned up the heat with a full-fledged invasion force violating Earth's airspace in the last moments of "City of Lost Children," while Supergirl (Melissa Benoist) could only stand by and watch the spacecrafts blanket the sky. Tomorrow night's new episode of Supergirl will bring viewers one step closer to the end of the season with the first of a two-part Supergirl season finale and, as that Daxam invasion fleet suggested, this will be a finale of epic proportions, even within the DC Cinematic Universe. Showrunner Andrew Kreisberg teases that two-parter with news of Tyler Hoechlin's return as Superman and the reprisal of another major Supergirl character.

Supergirl Faces a Real War as Rhea Transforms Earth into New Daxam

After Rhea (Teri Hatcher) tricked Lena Luthor (Katie McGrath) into building the portal that allowed Daxam forces to invade Earth, Entertainment Weekly reports that Supergirl will have to enlist every ally she can muster to combat this latest threat. That means turning to some unlikely allies, like Lillian Luthor (Brenda Strong), to battle unknown forces.

Even as Supergirl teams up with past foes, Andrew warns that Supergirl will be facing off against more than one enemy in the two-part season finale.

"There's multiple showdowns coming up," Supergirl executive producer Andrew Kreisberg teases. "These are some of our biggest episodes we've ever done."

Supergirl, Teri Hatcher, Rhea
'Supergirl' centers a mind-blowing season finale around Teri Hatcher's Rhea. [Image by The CW]

Kreisberg adds that the series producers have saved on budgets from previous episodes in the season and specifically earmarked that saved money for this season finale. He says the added funds have been used to enhance visual effects and also to add an additional day of production. From the beginning, it was determined that the two-part season finale would be the biggest Supergirl episodes ever produced.

Andrew adds that, while this will be an explosive story, there will also be some highly emotional scenes, so he suggests keeping the tissues handy.

Supergirl Brings Back Old Favorites

Supergirl, Calista Flockhart, Cat Grant
'Supergirl' brings Calista Flockhart back as Cat Grant. [Image by The CW]

As Culturess shares, Supergirl will lean on some familiar faces, once she realizes she's going to need help from more trustworthy allies. Among those joining the team will be Superman, as Tyler Hoechlin reprises his recurring character, but possibly more exciting for Supergirl fans is the promise that Calista Flockhart will return as Cat Grant for the double episode season finale.

Supergirl will be forced to make some very troubling and difficult decisions in the season finale, says Kreisberg, and she will need to seek out advice from the wisest people she knows. That includes Superman, obviously, but also Cat, the one positive female role model who even Supergirl admires.

Speaking of familiar names and faces, the Supergirl boss revealed one more shocking spoiler, as he revealed that Superman villain General Zod (Mark Gibbon) would play a vital part in the finale.

"It's a great moment," Kreisberg says. "We needed a big, iconic Superman villain, and there really isn't anybody more iconic, at least in terms of a physical opponent for Superman, than Zod."

The Supergirl showrunner also revealed that the two-part finale would bring everything together, joining several story arcs that have been playing out throughout the season. Specifically, Kreisberg mentions "Superman and Cat and Cadmus and M'Gann and Mon-El and Lynda Carter and now Rhea" as all playing a part in this epic Supergirl story.

"Say whatever you want about the finales, they're not boring," Kreisberg adds with a laugh.

Part 1 of the Supergirl season finale, "Resist," airs on Monday, May 15 on The CW.

Part 2 of the Supergirl season finale, "Nevertheless, She Persisted," airs on Monday, May 22 on The CW.

[Featured Image by The CW]