Batman has been stuck in the same cycle for 70 years. As soon as the “Dark Knight’s” mythology becomes too dark, he is reinterpreted through the faddish lens of pop cultural parody. Consequently, Batman’s legend lacks substance. So he’s reinterpreted once again with darker shadings. But “The Dark Knight Rises,” the final chapter in Christopher Nolan’s epic addition to the Batman myth, looks past both interpretations. As Nolan promised us from the beginning, his trilogy offers a realistic superhero. But can there really be such a thing? Should there be?