Cas watched as your hand shook Dean's, he felt his heart drop into his stomach and he squeezed his eyes shut. He'd failed, failed keeping Dean safe from the likes of you. He's sick of you trailing Dean down such a dark path.

"You disgusting little..." he waited for Dean and Sam to leave before pinning you to a wall. "Your information better not be faulty. If you lead them down a road of pain and suffering I'm going to make sure it's tripled and inflicted upon you."

Castiel doesn't trust demons. He's been proven right a million times. Now, with Abaddon on the run he had even less of a reason to trust. You were an ancient demon, you're supposed to be crazy, wild, evil.

You weren't supposed to have humanity in you still, "Something smells like sulfur, and I don't want it to be you."