Castiel couldn't help the confused look on his face, head cocking to the side almost innocently. "Changing?" His wings jerked slightly, still stretched out before he drew them in closer to his back. A flash of light against one wing seemed to show sharper feathers, but the flash was gone in an instant as well.

"It could be from my prolonged time here. Humans become demons...perhaps angels become something as well." He shrugged as if it didn't matter to him before moving closer to the demon, smiling.