You would be surprised how many directors don't know what they want. They might not know what they want until they see it, they might know what they want but no idea how to get it out of the actor, then you've both got a problem.
Ian MckellenElijah looks angelic but his beauty of spirit is what makes his Frodo leap out of the screen. Unalloyed goodness is one of the most difficult attributes to act.
Ian Mckellen