After she killed time on a flight by watching the History Channel’s “Vikings” series, Anna Sui became obsessed with the show and its “sexy, racy gorgeous cast and setting.” The question at collection time was, how to use it? She happens to be an interiors enthusiast (with a recently launched home collection in Japan), as were the Vikings’ fellow Scandinavians with their fertile midcentury period, Marimekko and other purveyors of bold textiles — which lend themselves nicely to fashion. And Sui had a field day mingling these Nordic references with her signature genre of bohemian rock and mixing a feel-good soundtrack of Abba songs to go with the show.