 Green starred in the first season of Starz 's series , Camelot , as the sorceress Morgan le Fay . Green stated , " This is such an iconic story and you have 10 episodes to explore a character . It 's not a girlfriend role that you could have in a movie . It 's a real ballsy character . She has some guts . " In 2012 , Green played a vengeful witch Angelique Bouchard who curses Johnny Depp 's character into a vampire in Tim Burton 's Dark Shadows . In 2014 , she played Artemisia in the 300 sequel , 300 : Rise of an Empire . Since May 2014 , Green starred in the Showtime series Penny Dreadful as Vanessa Ives . She played the titular role Ava Lord in the Sin City sequel , Sin City : A Dame to Kill For ( 2014 ) . 
