Should be in Legend of Mori Motonori. It was 3rd last mission. I head my army to attack Tokugawa Ilyasu son's army. The battle was initially easy, I swept aside any resistance that came to me.When I reach the enemy's town. Suddenly out of no where the enemies get a 2 full battalion reinforcement and they keep on respawning. One by one my samurai lost but I kept on the attack ( my samurais was 42 down to 14 now ). Few turns later, the enemy got 1 more battalion reinforcement and they appear just behind my main camp. I have to repel them or else they'll cut my food supply. So I have to sent my ninjas ( as they can move fast ) to defend my main camp while my remaining unit move as fast as they can to follow the ninjas. It was a hard fought battle, after eliminating the reinforment army. I was only down to 5 samurais. I stubbornly went on assaulting the town ( where Tokugawa son's is defending ), Somehow I manage to break through the defense and manage to land a killing blow to Tokugawa son's. The battle was finally over! I was really relieved as I was down to my last samurai and he only got 10 hp left. phew!
