The Doctor nods. "When I first met him, I thought he was more a prankster than anything. But the more times we encountered him, the more stories I heard about him, I learned there was a deep malice to whatever he did."

It's hard to explain, because honestly for the Doctor, it's more a feeling he gets than anything else. His emoji doesn't change from the puzzled expression this time. Though, there's still a scowl on his face, which says enough.