THAT IS AMAZING. ARTHUR'S EXPRESSIONS ARE PERFECT. 'That's very interesting.'

You make a good case! Morgana could very well be a Slytherin. I do think Ravenclaw is a possibility, though. (Although, when I really think about it, I can't find an argument for picking Ravenclaw over Slytherin beyond 'MORGANA IS AWESOME. RAVENCLAW IS AWESOME. THEREFORE, MORGANA IS A RAVENCLAW'.)