Appropriate Obstacles

I was thinking this morning about the "Superman Problem," which is my word for the idea that Superman, because he is so powerful, isn't interesting because the obstacles he faces are never sufficiently challenging. There's an obvious solution to the Superman Problem, and the best comicbook writers know it and use it all the time: give your powerful characters obstacles that challenge them in different areas than the ones they're strong in. So for example, in the excellent Kingdom Come...