SPOILER WARNING: This article contains major spoilers for “Make It Reign,” the latest episode of Supergirl.
The CW's Supergirl just borrowed a page out of Man of Steel's book. In "Make It Reign," the penultimate episode of Season 3, Kara and her team discovered the Dark Priestess' true mission: to terraform the Earth in Krypton's image.
Last week, Serena and her Dark Priestesses stole Kara's ride. Using J'onn J'onnz's ship, they made it back to Earth, where they started their Worldkiller efforts anew. This time, however, their true goal became clear; they revealed Reign would dive down into the planet's core and kickstart a cataclysmic event, which would destroy all life on Earth and pave the way for a new Krypton.
If that sounds familiar, that's because Zod tried the something similar in 2013's Man of Steel. Using machines called World Engines, Zod hoped to wipe out life on Earth and use the Codex embedded in Superman's DNA to build a new Kryptonian race. Of course, Superman put an end to Zod's reign of terror by defeating the general's army and snapping his neck.
Per the promo for “Battles Lost and Won,” the Season 3 finale, Kara will attempt to make a less deadly approach to stopping Reign. In the brief preview, she insisted she doesn't kill, "not even her." However, that remains to be seen in next week's episode.
Airing Mondays at 8 p.m. on The CW, Supergirl stars Melissa Benoist as the Girl of Steel, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott, with appearances by Calista Flockhart as Cat Grant and Tyler Hoechlin as Superman.