Supergirl: Reign Heralds the End of Days in Midseason Finale Promo

The Worldkiller has arrived in National City. In "Reign," Supergirl Season 3's midseason finale, Samantha has undergone a startling transformation, and that spells trouble for the Girl of Steel.

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"It's here. The end of days. And in its wake, many cowards and killers and vile men will burn," an ominous voice narrates over the promo as Kara seems to discover Reign's Fortress of Sanctuary. "And they will call it, 'Worldkiller.' Her rise will come at the fall of the righteous, and she will reign."

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At the end of “Wake Up,” the last non-crossover episode of Supergirl, Samantha made her involuntary transformation into the Worldkiller known as Reign. After discovering her Fortress of Sanctuary, she learned she was destined to raze the World of Man and become the Worldkiller, something much more powerful than other Kryptonians. She was then informed her that she would be purged of all her human emotions and memories. Samantha was horrified at the idea and refused, only for the Fortress of Sanctuary to make matters into its own hands and promptly removed any humanity Samantha ever had. Thus, her transformation into Reign began.

These changes are noticeable in the "Reign" trailer. In one scene, she doesn't even turn around when her daughter Ruby calls for her. Her face appears hard and emotionless as she stalks through CatCo in another. Towards the end of the trailer, she pulls open her button down shirt, revealing a Kryptonian costume and Worldkiller insignia underneath.

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"Take your best shot," Kara tells her at the end of the trailer, which cuts before the two swing into action.

“Reign” – REIGN CHALLENGES SUPERGIRL – Supergirl (Melissa Benoist) investigates a mysterious symbol popping up all over National City, tracing its origins back to an ancient prophecy and the mark of the World Killer, Reign (Odetee Annable). Meanwhile, the tension between Lena (Katie McGrath) and Morgan Edge (guest star Adrian Pasdar) continues to build, causing James (Mehcad Brooks) to step in and offer up some protection, and possibly igniting a spark in the process. Glen Winter directed the episode written by Paula Yoo & Caitlin Parrish (#309). Original airdate 12/4/17.

Airing Mondays at 8 p.m. ET/PT 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.

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