Corruption is how the world tells you it is running out of time. A forest near a lit hearth looks ordinary. The further the night has spread, the more that same forest curdles — colour drains, bark splits, the ground stops looking like something you want to walk on. Technically this is driven by a material parameter collection: one global set of values that every affected material reads from. Turn the corruption dial up and the whole biome responds at once, no need to touch individual assets. Runtime Virtual Textures let us blend the corrupted ground layer in cheaply across a large area, which matters when the map is World Partitioned and most of it is streamed. The hard part was not the tech, it was the timing. Corrupt too fast and players never trust anywhere; too slow and the threat feels theoretical. This pass is our first honest answer to the question the whole world hangs on: how quickly should a place you know stop being safe?