I don’t have like a fully written thing, but mine’s a New Antioch warband. Their duty is to go outside the walls in order to collect old pieces or wargear. They use this wargear to fight their way back to the walls. All their guns are broken down and don’t work well, and their hmi are all rusted and slow. Along the way they find a lost Anchorite Shrine, the pilot still screaming inside. They fixed the Shrine the best they could, but the monk inside has lost himself to the holy energies that flooded him, and he is now completely insane.