How does Youjo Senki end? Carlo Zen's novels run thirteen volumes deep — the screen has covered barely a slice
Saga of Tanya the Evil is back on screen, but the novels stretch far beyond anything animated so far. What Carlo Zen has published, what he hasn't, and what that means for the ending.
I have wonderful news and terrible news, and they are the same news: nobody knows how Youjo Senki ends, because Carlo Zen hasn't ended it.
The light novels have been going since 2013 and have piled up fourteen doorstopper volumes in Japan — and these are not normal light novels, these are bricks with footnotes about artillery doctrine. The current arc carries the cheerful Latin title Dum spiro spero — "while I breathe, I hope" — which, for a series about an empire winning every battle while visibly losing the war, is the funniest possible flex.
What the screen has actually shown you
- Season 1 (2017) plus the 2019 movie: roughly the first three volumes. A slice. An appetizer. A single vitamin.
- Season 2: airing right now, the first new TV season in nine years, and it still leaves a mountain of unadapted text behind it.
So when someone asks "how does it end," the honest answer is: the Empire is deep in its "we keep winning and it keeps not mattering" era, Tanya keeps getting promoted into worse and worse situations, and the finish line exists only in Zen's head.

The author would like a word
Zen has always been upfront that this is a WWI-flavored thought experiment, not a history lecture, telling Anime News Network:
"It's a story, not a textbook."
Which is author-speak for "I will end this when I end it, and you will read every page of military logistics on the way there."
Bottom line
If you need closure, Youjo Senki is not currently selling any. If you need thirteen-plus volumes of a tiny blonde war criminal filing complaints to God mid-dogfight — congratulations, you're covered for months.