Princess Sidonie oversaw the placement of the different Demon Clans after knowing each of their specialties.
The lands that William had given them surrounded the Deadlands, which William had taken from the Void when he returned to Hestia. His general plan was to let the nine Clans that had sworn allegiance to him slowly rebuild the city, with the techniques that he would teach them after they had settled down.
The Half-Elf knew that rebuilding the Deadlands from scratch would be a time consuming process. He could use his God Points to fix it completely, but the cost would be astronomical. Because of this, Optimus gave a suggestion that William only use the God Points for an electrical grid and plumbing, so there could be light and a clean source of water that would allow the city to regain its basic functions.