The Finest Hour

The Finest Hour is the 3rd volume in the Youjo Senki Light Novel series.

Short Summary
The Empire strikes back! Tanya and her battalion commenced their mission to end the war.

Will the war end in their own hands?

Another heroine bless with protection. Who might be this person?

Chapter VI: The southern campaign
That ends 400+ pages of vol 3.

Reference
Thanks to u/MSG_Johnny2 who posted the summaries at r/YoujoSenki.