I think Hannibal generally has a soft spot for Margot, not saying he wouldn’t eat her, of course. He absolutely would. He would eat someone either way. Just that his encouragement of her killing Mason seemed passionate in that it felt to me as though he was rooting for her success. Hannibal’s world is a slaughterhouse and within it, he would have liked to see Margot gain the upper hand to a certain extent, although under his attention, she was doomed from the very beginning anyway. Hannibal’s intentions are always genuine bar him actually hiding said intentions because in truth no one (except Will) would accept to see things in his perspective. And I felt that all his conversations with Margot had a very sincere mentor-ish vibe along with being the devil on the shoulder spilling poison for the sake of amusement. It’s also fun to see him croon to her about what she should do to kill Mason and then actually meeting Mason and being very openly disdainful towards him.