A Nativity world would probably resemble the corrupt land in CoC, with everything even the plants vaguely sapient and focused on reproduction wether its fruitless or not, to the point civilization nearly ceases to exist. Nativity victory is a semo-sustainable world that serves only its purpose of perpetuation and growth. Nativity would use the world like a battery, forcing its inhabitants to be the chemical reactions giving it power until they are all exhausted.