The real battle royale this summer isn't between Batman and Superman, or between Captain America and Iron Man, or between the X-Men and the purple guy. It's over the soul of blockbuster cinema. Marvel has clearly staked its claim, and DC announced its own perspective rather loudly a few months ago. The latter made a film which, while admittedly convoluted, was at least a stab at something grandiose and new. It didn't make logical sense, but it felt like it…