The Hax Rebellion Army flooded the forest with troops. The infantrymen armed with Weler-150, BC-75, and BC-79 advanced forward carefully. They surrounded half of the volcano because Hax didn't want to spread his forces too thin. He wanted all of his spears to attack at one single point.
Behind the infantrymen, a line of wagons followed. They had a little bit of trouble navigating through the forest, but with little time they managed to arrive at the foot of the volcano.
That was when a group of people brought out various wooden parts and assembled them into some kind of large slingshot.
It was a new device the blacksmith had made. When they heard the existence of the exploding ball, the blacksmiths knew what they had to do. They modified the traditional ballista design and change the smaller pouch where the arrow was placed into something bigger to provide space for the exploding ball.
They call it the ball thrower. Stupid name. Simple but stupid.