Flagg is the personification of evil, a demonic figure who wreaks havoc after a plague kills most of the population. He was played in haunting fashion by Jamie Sheridan in the miniseries adaptation. This is by no means a firm situation, but it’s understandable why the studio thinks McConaughey would be a compelling and persuasive force of evil in the film. Flagg was such a force of evil that King used him in several of his works including The Stand.Boy, this is a turn I didn't see coming. And if it comes to be, I think it'll be a good sign for The Stand.
Matthew McConaughey Might Enter ‘The Stand’
DEADLINE reports further progress on the cinematic adaptation THE STAND, reporting that Matthew McConaughey is "coveted" by Warner Bros to play the evil Randall Flagg, directed by Josh Boone.