Abyssus abyssum invocat

Abyssus abyssum invocat is the 5th volume in the Youjo Senki Light Novel series.

Short Summary
The power of blessing emerged in the surface.

Tanya and Mary sue have faced one another.

Who shall prevail?

Chapter IV: Long range assault operation
The General Staff gives new orders to Tanya. Once new recruits to replace the lost veterans

Chapter VI: "Liberator"
That ends 500+ pages of vol 5.

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