skygiants

But I think you could probably do quite a lot with staging and facial expressions and Anya having reactions to things that currently don't register.

Yeah: the kind of about-face you describe might be more believable if you could tell that her facing-down of Gleb was the last showing of the Anastasia mask, and now that it's kept her alive and broken the last link with her past, she can let it go. (I do not assume this is how it functions in the show, I'm just thinking of excuses for plausible emotional continuity.)

The confusion comes in, of course, via Princess Tutu, from whence also derives my primary attachment to Swan Lake

Legit!

Using Swan Lake as an inset for the Anastasia story is brilliant, however, since it concerns the impersonation of one woman by another—well, what if Odette is also impersonating Odette? What if there's no White Swan?