Drakengard/WMG

Before the pact, Caim is already mute.
That would explain that prior to the pact, he doesn't give out directions to his soldiers.


 * This is impossible. We clearly hear Caim speak before the pact in mission 1. "Empire scum, I will feed you to the ravens," etc... and clearly hear him speaking in one of the endings. It would be my guess that he is just too preoccupied with killing everything to be bothered by what his army is doing, not to mention the fatal back wound.
 * He's the one who proposes the idea of a pact to Angelus in the first place.