Oscar Isaac has launched a first-rate film career by creating characters nobody wants as their imaginary best friend. Over the past 10 years, as villainous King John in Ridley Scott's retelling of the Robin Hood legend, a sneaky CIA type in the latest Bourne film, a vile asylum orderly in Zack Snyder's "Sucker Punch" or the tragicomic title character in the Coen brothers' "Inside Llewyn Davis," he's played guys you'd cross the street to avoid.