AP#46 Brusilov Offensive
The Brusilov Offensive of June 1916 destroyed the Austro-Hungarian Fourth and Seventh Armies. The Austrians lost a staggering 1.5 million men (including 400,000 taken prisoner). These losses were definitely irreplaceable and effectively tolled the knell of the Austro-Hungarian Army.
To reflect this, I have added to the event’s effect that any AH army destroyed as a result of Brusilov Offensive was permanently removed.