Black Dragons

The dragon acts on the troops like a red rag to a bull. It cannot be taken down with magic, and it is immune to control and blinding effects, which means we have to immediately send all our soldiers against it. And while the enemy is busy killing dragons (and let them – we don't mind), we will destroy their army. We can get closer and skillfully disable their main forces. We kill the main units, and they only kill a dragon.