Somehow Yahya Abdul-Mateen II isn’t a household name yet, but, boy, that’s about to change. Despite portraying Black Manta in the blockbuster “Aquaman” along with roles in “The Greatest Showman” and “Us,” the New Orleans native was one of the more under the radar actors when Damon Lindelof’s “Watchmen” mini-series debuted last year. And that might have been his biggest asset as he transformed from the quiet Cal Abar to Dr. Manhattan in one of the biggest twists in television history. Oh, but just you wait.