Even the greats like #LéaSeydoux sometimes experience cycles of self-doubt. On set of “The Unknown,” one of her two films competing at #Cannes this year, Seydoux found herself consumed by recursive thought processes. “I’ve never done any theater school. I learned to act in front of a camera,” she recalls. “So I feel that I’m almost an unprofessional actor. I’ve done so many films, but I’m still sometimes like I will never be able to do this.” But to read through Seydoux’s list of credits is to grasp her talent for transformation: she’s an actress who pushes to the edge while becoming someone else. Since her Palme d’Or-winning breakthrough in 2013 with the frankly sexual, emotionally walloping “Blue Is the Warmest Colour,” Seydoux has become a staple of world cinema. She’s lent that style and edge to the James Bond franchise (where she played Daniel Craig’s one true pairing, the Proustianly named Madeleine Swann) and to “Dune: Part Two” (where her sly Bene Gesserit noblewoman has big ...