Arrow: Katie Cassidy Returning as Series Regular for Season 6
Cassidy will reprise her role as Black Siren in the final two episodes of Arrow's fifth season and will continue playing Laurel's villainous doppelgänger as a series regular in Season 6.
Cassidy was a series regular on Arrow's first four seasons playing Laurel Lance, an attorney by day and the vigilante Black Canary by night, until her death at the hands of Damien Dahrk (Neal McDonogh) last April.
Cassidy then returned in Arrow's most recent midseason premiere when Black Siren impersonated Earth-1 Laurel to mess with Oliver's head on Prometheus' (Josh Segarra) orders.