The World Pump obeyed and built walls that turned its interior into a snail's shell. This created one long hallway from the entrance that looped around the World Pump's core over and over again until it reached the core.
He would have loved to seal the entrance completely, but he couldn't because he needed a continuous passage from the entrance, through the connection between the World Pump and the glass shield, to the core to allow the essence extracted from the world to reach the pump.
So he could have created a maze or a series of rooms between the core and the entrance. But whatever he created, there has to be at least one viable passage from the entrance to the core for the world essence to flow through. This too was a weakness of the World Pump.
By creating a hallway, he increased the distance the attackers had to travel to reach the core. Next, he needed people to defend the core and prevent the avatars from reaching it.
