That General Swanwick was actually the Martian Manhunter in disguise, a fact that would have been revealed in Justice League.
There is something to be said for Whedon’s decision to exclude the Martian Manhunter from the Justice League.
In the comics, the Martian Manhunter is an alien superhero who makes Superman look underpowered by comparison.
The finished movie found no mention of either Swanwick or the Martian Manhunter, leaving fans with a dangling plot thread and dreams of what could have been.