Dogs of war

My name is Rex. I am a good dog.
Rex - a dog, two meters tall, covered with light armor and equipped with large -caliber weapons, and his voice is configured so that the resonance causes panic fear of the enemy. With a dragon, patho and swarm, it makes up a storm flock of multiforms. They are used for military and police operations in Kampuche, the southeastern state of Mexico - in the kingdom of lawlessness and anarchy.
Rex - a product of genetic engineering, biofors, deadly weapons in a dirty war. He has an increased intelligence, so as to understand orders and sets feedback implants that cause pleasure in their execution. All he wants is to be a good dog. This means fulfilling all the orders of the owner, and the owner orders to kill enemies.
But who are these enemies? What will happen if the owner becomes a war criminal?
What if the Geneva Convention prohibits such a weapon? Will Rex and other bioforms remain the right to exist? And what will happen if the Rex breaks off the leash?