Cas shook his head. "More that he touched me inappropriately and without permission," he replied bluntly. "It took me by surprise. And I didn't appreciate being ambushed. Namely because I'd just arrived in a strange place I didn't recognize."
Impulses were attached to emotions and emotions were not something Cas was in any way adept with. Rarely could he label them and even when he could, he was primarily and exceptionally uncomfortable with them. Aside from the most basic - sadness he understood. And anger. Love came much later, but that extended only to a select few in the platonic sense and one in the romantic. Beyond that, the emotions were responsible for many of his regrettable impulsive decisions.
"And when you're wrong, you not only begin to question yourself, but it's impossible to stop thinking of those your actions harmed. I'm aware of what you speak of. Very much."
His first hunt with Dean had not been successful. A boy had died. And even though there had been several jobs after that, including one that had ended in a shooting accident with Cas on the wrong end of the gun, the boy's face and name were still as clear in his mind as they had ever been. "I...don't know what Sliders is," he replied honestly. "Or Doctor Who. But to answer your question, I would have to say demons. But then...that is naturally ingrained. So tulpas will have to suffice."