The Forsaken were working hard to stockpile supplies, and Grimg, far away in the Blasted Lands, wasn't idle either.
After Leiluo and Varian reached an agreement, the Blasted Lands had become Horde territory through and through. Although Leiluo hadn't sent more troops there, he had maintained its military strength and quickly relocated a large number of civilians to the region. The Blasted Lands was no longer merely a military stronghold.
As governor of the Blasted Lands, Grimg was probably the busiest of all the Horde governors. He was a warmonger, so he had developed the region's arenas on a large scale. From time to time, he would personally enter the ring with his two inseparable friends, Gobard and Gulu, promising generous rewards to anyone who challenged him. That was why even humans from the Kingdom of Stormwind flocked to the Blasted Lands: arena fighting really could make you money.
Of course, Grimg made the most money of all. Many human nobles, cowardly yet hungry for thrills, enjoyed arena combat. They craved blood and the sight of others being robbed of their lives, so they were willing to spend huge sums on gladiators and send them into deadly matches to satisfy their twisted souls.
Once Leiluo's orders reached the Blasted Lands, Grimg shut down every arena, drove out all the humans, and gathered his army, preparing to wage war against the Kingdom of Stormwind.
The Alliance couldn't possibly have failed to notice the Horde's massive mobilization. In the past, the Alliance would certainly have backed down, but this time Bovar contacted the Arakkoa in Arank Peak Forest and paid to hire a large number of Ogres. These two races had deep-seated hatred for the Orcs, and he tasked them with holding back the Horde army as it tried to march