Unfrotunately, this series has retained all of the problems from the precursor series and then some.
It seems that religion has been thrown almost completely out of the picture as "Being X", a deity and the main antagonist of the series, has been largely succeeded by a vengeful but naive girl, who is there for a vendetta and justice and who is an incompetent soldier, but a good mage. The fact that she is named "Mary Sue" should tell you all there is to know. Like the antagonist from the precursor series, she would have been a wasted character if the series did not end with this movie.
The dialogues have taken a step back in the movie:
"You killed my father!"
"What did I do to you?"
among other similarly odd exchanges.
Unfortunately the platitudes of the MC that become more and more contradictory also continue. Like calling the nearly dead vengeful girl an animal (in the previous series the MC called humans irrational animals) because of her vendetta, especially in light of her own actions, is rather confusing. I assume this is likewise meant to be good, artsy, and intriguing dialogue, but it just comes out as non-sensical.
In the movie, the MC, being an advocate for free-market economics and an actual imperialist, seems to utterly despise the equivalent of the USSR for being communist and totalitarian. Generally the idea of hating communists is repeated an awful lot, and there is plentiful reason for that in the movie. Communists shoot each other, send soldiers to die in waves, have a massive bureaucracy and are ruled by incompetents and pedophiles. It even turns out that a secondary character is the equivalent of a Russian Imperial emigree. It would appear that the creators themselves had a grudge against the communists, were it not for Mary Sue who displayed neutrality. It is more likely derived from actual 1930s relations of European nations and the USSR. This also comes into a weird contradiction with the previous series, where one of the symbolisms displayed there was a fountain resembling a similar fountain from Stalingrad from a famous photograph. Instead, there is the more famous scene of the Soviet troops putting a flag over the Reichstag, except it is the Imperial soldiers with one of the buildings in the Kremlin equivalent. Added together with the reference to the Cessna landing in Red Square and the Palace of the Soviets (but with a Stalin statue instead of Lenin) these amount to the only new pieces of symbolism in the series. Basically, the whole thing with the USSR equivalent seems to be some kind of satire/caricature of the actual communists, and the authors made sure to show who is who in leading this country. The problem with this whole segment is that were this satire an actual political gesture, then it would be in context. But this is in a very vague context, where in general other countries are more like placeholders. Randomly bringing forth these convictions from real life is of questionable use in this particular plot.
The way that the MC talks about the real Great War is also confusing. While this war is big in scale, the MC has no real proof of it becoming a world war, least of all because it is not shown that countries and colonies further away fight like they did in a true world war. In this anime, the conflict is pretty much locked to the Europe equivalent, whereas in WWI there were entire campaigns in Africa, Asia. and on the high seas. It was true imperial juggernauts mustering all of their colonies in a decisive war. And yet the MC is certain that this war will be a repeat of WWII.
The animation is alright, but the CGI now starts to lag considerably as compared to the original series.
Generally writing about everything else, from the theme limitations to sound, would be to repeat these attributes of original series.
I recommend watching this just to either conclude watching the whole series or carry on into the next series (if there will be a continuation). It is not really worth otherwise. It is a bad tradeoff to watch it for communists at the expense of everything else that made the original series good.