The question of Ruby and her faith, of what she had faith in, always interested Castiel. He was always convinced there was more to the answer than she gave, but quite what he had no idea.
Not that the answer she gave was a lie, he knew that too. Her relationship with Sam was complicated, one that he was never sure what he felt about it. And as for him...
"She's not a monster," he emphasized quietly. "Demons are complex creatures," he spoke to Margareta directly now. "What a mortal sees of them is just the surface, trust me when I say nothing is ever simple where they're involved. I love her, and I believe in her. Do you trust my judgment?"