I loved this episode, as I've been enjoying this whole season so far!
I found a big theme for me here was how people often are very aggressive because of our own insecurities and fears, like how you see Becka being such a fierce witchhunter because she was afraid of what happened to her, and her fear of her own possession. She felt she could exorcise her demons by finding them in others, and you see that happening so much in real life. And James, with his own fears about his knowledge and understanding, tries to portray himself as such a holy warrior, and I love how the Doctor realizes this and she almost gets through to him. You could tell he was really having doubts about ordering her to be put under water, but he gave in to his ego, even at the end when he killed Becka.
Graham looked adorable in that hat! Ryan and Yas continue to be perfect for me

I really enjoy how much confidence the Doctor has in her companions, how she'll send them out on tasks, and while she obviously is protective of her charges in a way, she has complete faith in each of their abilities and you can tell she trusts them deeply.
I didn't even realize that was Alan Cumming playing King James, though he seemed familiar, and I obviously saw his name in the credits! This is one I definitely think I'll rewatch again, especially just to see his performance
I also found it very refreshing to see an episode dealing with sexism and its effects.