Izetta is powerful enough to fight whole armies, but her strength is limited.  She can only use her abilities near certain ley lines, and outside them, she's no different than a normal girl. When the Germanian army attacks in a spot far from these ley lines, the duchy is forced into a corner: how can they repel these foes without giving up the secret of Izetta's strength?
But why expose Izetta herself to the enemy?
لكن لماذا تكشفُ إيزيتّا نفسها أمام العدوّ؟
Aber warum musste Izetta
persönlich vor den Feind treten?
Pero ¿por qué exponer
a Izetta al enemigo?
Pero ¿por qué exponer
a Izetta al enemigo?
Mais pourquoi avoir mis Izetta
juste devant l’ennemi ?
Ma perché esporre personalmente
 Izetta davanti al nemico?!
Mas por que expor 
Izetta para o exército?