Bab 1354: How To Beat Warriors.

Legion-5 said with disdain, "You better do that." 

Then he warned, "And don't play any tricks. Bring out exactly what I asked for and nothing less. My patience has already been pushed to the limit with your attempt to negotiate with me so expect swift punishment if you try me again."

The supreme beast returned to his base and began sending orders. Golems moved about immediately. They brought out carts of resources one after the other. Because there are a lot of resources, it will take time to bring out 10% of it. Legion-5 was willing to wait and act like he didn't know what they were planning.

Their mobilization of troops was secret enough. In fact, they didn't have to try much to keep it from him. But they can't hide the amassment of troops and the mobilization of said troops as soon as he left his base from Legion-7.