This is by no means a good movie. But it might be one of those so-bad-it's-good kind of films. You have to accept from the outset that this movie is completely absurd; it's a flight of fancy about an alternate WW2 where magic and occult mystical powers are real but kept secret.
It is well known that on the German side the high ranking SS were very obsessed with theosophy and occult matters and imagined themselves as the spiritual successors of the ancient Teutonic Knights. This actual quirk of history gets riffed on in this anime and made literal in the story.
The Russians for their part have their own quasi-mythic heroes of the ancient past, like Aleksandr Nevsky, who dealt the Livonian order of the Teutonic Knights a crushing defeat and has been invoked by Russian Tsars and Soviet officials and contemporary Russians as a national hero. Nevsky was a real historical figure, but his legacy takes on mythic proportions over time as a potent symbol of Russian patriotic resistance to foreign invasion, part of national mythology in the same way a figure like Abraham Lincoln for America or George Washington and the cherry tree have these larger than life mythic qualities attached to them.
These competing embellished myths, more than actual history itself, are the material from which the ridiculous story of this anime movie was spun. This movie shouldn't be taken seriously, and the use of live action documentary footage clashes tonally with the rest of the animated portions of the film...it tries to add an element of realism to an utterly absurd tale and falls completely flat. One wonders if this inclusion was at the behest of the Russian side of this production and the Japanese staff simply acquiesced to the desires of their Russian collaborators who wanted to tell a more serious story about their Great Patriotic War while the Studio 4C people just wanted to make an exciting (if patently ridiculous) movie. If this movie were re-edited and the live-action cut scenes cut out it might be salvageable as an engaging action film of fantasy history.
I don't know why Nadya has a Katana....she's a war orphan, former Young Pioneer, and has psychic powers. Maybe she had a grandfather who fought the Japanese in the 1905 war and this was a war trophy / family heirloom....best not to think too hard about it. She has it because "anime"; no deeper reason is really necessary.
This movie is worth a watch for just how WEIRD it is. It's a failed experiment, but a pretty glorious failure. If you accept up front how utterly absurd it is, it will help you actually enjoy this film. If you're hoping for a serious account of the Soviet experience during WW2 in anime form, you've come to the wrong movie.
