This well-received series adaptation of a DC Comics character ends its six-season run with two final back-to-back episodes, starting with "The Last Gauntlet," which sees Supergirl (Melissa Benoist) and her super allies taking desperate action after Nyxly and Lex Luthor (Peta Sergeant, guest star Jon Cryer) kidnap a loved one. Then, former cast members Mehcad Brooks, Jeremy Jordan and Chris Wood return for the finale "Kara," wherein Alex and Kelly (Chyler Leigh, Azie Tesfai) prepare to wed even as Supergirl has a final confrontation with Lex.