Castiel was, fortunately, not listening to Aziraphale or Crowley. Crowley struck him clearly as a thing apart, not quite angel, but he didn't immediately seem hell-ish, either. Perhaps it had been too long since he'd been down there, or Castiel was used to looking for quite different demons altogether. No, for the most part, Castiel was focused on Lorne, a being from another dimension. He hadn't any idea Lorne was actually called a demon, as he would hardly classify someone as much, not having an inherent problem with green skin.
Lorne's last word caused Castiel alarm. Removed?! He hadn't thought of it that way. The light made a sound like a dying rabbit in a huge gong, echoing off the psychic ears, and then he flashed at the door in an attempt to get out.