She's not your concern, was the immediate response, but Karl held back in starting a new conversation that had nothing to do with what was at hand. Alyssa had her leave earlier and now Karl was taking one. Although he found himself content with what had happened during Valentine's Day and with all of his choices made with his partner, the Warfare god still had minor concerns about his own behavior. More and more, he was focusing on the human side of his nature - and while it was not entirely a weakness, it wasn't one that he could come to terms with entirely.
Not when there was a war going on, and not when the outcome would be decided by his efforts along with the others. This little "exercise" was needed to remind him just where he stood once more. The idea of Death effected him far more than any moving force, and to suffer even a temporary moment of it through a bullet was enough to get him back on track.
He continued to stay silent while he busied himself to loading the bullet and spun the chamber, letting it whirl as he let his attention focus entirely onto the matter at hand, making his peace with other events. For all he knew, he probably wasn't going to walk away from this intact, and that meant there was no point in thinking too much.
With a practiced flick of a wrist, the chamber snapped back into the gun; locked and loaded with that one fatal bullet.