Odette Annable has been cast as Reign for the upcoming third season of CW's Supergirl, according to Deadline. Annable's Reign is described as the primary villain of the 2017-2018 season, and will be a series regular.
“Greg [Berlanti] and I have wanted to work with Odette for years,” said Supergirl executive producer Andrew Kreisberg. “We are beyond excited to have her join our cast in the scary, powerful and heartbreaking role of Reign.”
Reign debuted in early issues of "New 52's" Supergirl title as a genetically-engineered meta created by Kryptonian scientists based on an unknown alien creaure. She became the leader of a group of villains called the Worldkillers.
Annable recently starred in CBS's Pure Genius, and before that had a regular role on Fox's House M.D.