To create the scene each Superhero was photographed individually.  To achieve the sense of realism the lights were positioned so that the main light source was concentrated on their faces.  This replicates the light coming from Captain America's shield as the Superheroes clash.  We also used an edge light to provide separation from the background with a soft fill light to bring out the detail in their costumes.

Achieving realistic lighting and perfecting the pose is just the first half the process with Mat's skilful editing bringing it all together.