Cas ducks out of the gun's swinging path, inwardly cringing a bit - but only a bit; this is merely a shadow, real as it may feel - at the sound of impact. The Shadow is knocked to the side, losing its hold on Phil, and not a moment too soon considering the color Phil has turned.

Before it can rally, Castiel pivots and catches the creature, thrusting it away from Philip and Dean, pinning it against a nearby tree. It's a move Dean will see often enough in the future: an angel overpowering another creature as much with invisible as with physical strength, pinning them high against a wall. Castiel isn't one for excessive dramatics though, and he likes the satisfying physical feel of the creature held immobile by his hand. "Silence," he tells it. He has words for the real Phil, but he'll wait until he's recovered enough to hear them, and hope his and Dean's strength will be sufficient to hold the Shadow at bay until then.