John set up the trap on the mountaintop by using the Illusionist's Illusion Copy and Invisibility Shroud.
He knew Linda would attack his command base at one point, so he constantly had illusionists make a copy of himself, the war table, and the guild players with their platforms above the mountaintop. The Illusion Copy lasted two hours. Every two hours, the defenders lined up and covered these copies from the enemy's sight while the illusionists produced another copy. After the copies were in place, the defenders spread and let the enemy see John and the others again, keeping the illusion that they were always there on the mountaintop.
