A surprise candidate

The cast of characters in Captain America: Civil War is huge already, but there’s every chance that some surprise appearances could be made by existing Marvel Cinematic Universe characters who aren’t scheduled to appear, or even by some new characters who haven’t been listed.

Thor or the Hulk, for instance, could be drawn back to Earth to end the conflict that their friends are taking part in. Or the Guardians of the Galaxy could appear to tell the heroes on Earth to unite in order to prepare for the coming of Thanos.

Moreover, someone like the imminently arriving Doctor Strange could step in to pacify the quarreling heroes, or a cosmic hero like Nova, Adam Warlock, or Quasar could do the same thing. It would be a nice surprise for something like this to happen.

Then again, the conflict might not be settled by anybody at all.