Varang, the seductive leader of the Mangkwan clan—also known as the Ash People—is the most dynamic character in Avatar: Fire and Ash. She’s physically powerful (and often wielding flaming arrows or dual blades); she’s full of rage and intensity. And she’s brought to life by Oona Chaplin, who’s best known for playing Robb Stark’s ill-fated wife on Game of Thrones—and for being the granddaughter of Charlie Chaplin, as well as the great-granddaughter of Eugene O’Neill. But back when she first auditioned for the third film in James Cameron’s epic film series, Chaplin was as far away from the world of showbiz as she could get: living in a tree house she built herself in Cuba. “There was very, very little in this world that would’ve taken me out of the tree house. But the call from James Cameron certainly did,” she tells Vanity Fair. Before decamping for Cuba, Chaplin had been working in the Calais Jungle—a refugee and immigrant encampment in the vicinity of Calais, France. After that incredibly difficult experience, she needed to go …