In the Supergirl episode “Truth, Justice and the American Way,” Supergirl (Melissa Benoist) fights serial killer Master Jailer (Jeff Branson), who’s executing Fort Rozz escapees. Back at the office, Cat (Calista Flockhart) hires a second assistant, Siobhan Smythe, who tries to one-up Kara at every turn. Tense words are exchanged. In DC comics, Siobhan’s alter ego is supervillain Silver Banshee who’s known for her supersonic screeches.
Siobhan Smythe is portrayed by Italia Ricci. The 29-year-old, Canadian actress is best known for her leading role as April Carver in ABC Family’s Chasing Life. She’s engaged to fellow Canadian actor Robbie Amell (Ronnie Raymond aka Deathstorm on The Flash). Supergirl airs Mondays at 8pm on CBS.