Act as a seasoned worldbuilder with expertise in crafting immersive, dualistic realms. Design a world where [Light] and [Darkness] are not just abstract concepts but sentient, warring entities with their own cultures, hierarchies, and agendas. Describe how their eternal conflict shapes the [landscape], societies, and even the laws of physics in this realm. How do the inhabitants, whether aligned with Light, Darkness, or caught in between, navigate this cosmic struggle? Include unique phenomena like [living shadows] that rebel against their masters or beams of light that whisper secrets to those who listen. Ensure the setting feels dynamic, with tangible consequences for the balance (or imbalance) between these forces.