The Greatest Magicmaster's Retirement Plan: Volume 18 by Izushiro

Having somehow managed to reconcile with Theresia, Tesfia and Alus challenge the nobles’ war game, Tenbram, with their futures on the line. However, they face the sly enemy general’s Aile’s plethora of traps and outlandish schemes! During the fierce battle, Tesfia is cornered and a major accident will turn her fate around!

It is finally the climax of the Tenbram arc!