In the historical notes, you mention that Anastasia and her mother kept diaries. Anastasia's diary entries were useful because they gave me a clue to her personality, as well as some information about what she was doing at various times. I had fragments of her sisters' diaries as well, to help fill in the gaps. Anastasia and her sister and brother were Russian born and probably used only the Julian calendar, but Mama was from Germany, which had switched over to the Gregorian calendar, and she adopted the habit of using both dates in her diary. This became an important issue when events in Europe began to affect what was going on in Russia.
Bad guys are always fun to write about.
This doesn't mean I would have wanted to spend an evening with him. You fell in love with the story of Anastasia years ago. It would make a wonderful companion book to her diary. Your book hints at the unsavory and amoral character of Father Grigory. People in Anastasia's time either loved Father Grigory and considered him a great healer, or they despised him and thought he was a fraud.