For the character this episode is based around, see Samantha Arias.
"Who is she?"
"World Killer. The one who will bring about the end of times. This is your purpose, to fight the Devil."
Kara Danvers and Thomas Coville

"Reign" is the ninth episode of the third season of Supergirl, and the fifty-first episode overall. It aired on December 4, 2017.


Supergirl 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. Meanwhile, the tension between Lena and Morgan Edge continues to build, causing James to step in and offer up some protection, and possibly igniting a spark in the process.[1]