Billy's original plan in using the tunnels was to connect them to the enemy's base and then take the heads of the commanders. However, that would take too long. Even considering his skills, it would take a month to reach the northern camp. Naturally, just wiping out the leaders there probably won't be enough. No one had any idea where the commanders of those thirty thousand soldiers were, after all. Regardless, Billy asked for permission to make his group to stay on the Northern side of the battlefield. The Captains of the other battlefields wanted some explanation since they were the only reinforcements they could have if things get dicey. Still, the guild masters didn't just make a fuss out of it since they knew that Billy was plotting something to end the war quickly. They knew that he was that resourceful