Voidfall

I have always imagined it like Mirrodin except that instead of everything being made of metal, the landscape is still a natural mix of wood, flesh, stone, and ore but it has been altered by the Matron's alien power to look like Mirrodin. There is some substance that the Hive secreats into the earth that has over time caused this change, a byproduct of the Matron's brood. It has petrified some things, broken down others, warped and shaped parts of the land into a new ecosystem. Most plants and creatures have formed a chitinous shell of one kind or another, and in some cases this looks metallic, and can certainly seem made of stone or steel or just hardened shell. Others have unusual horns or hardened plates or spikes, or flesh or scales that looks like rock or silver or stranger things thanks to the chemical alterations. There is great variety and beauty to the Void, but it is a place utterly unlike any other in Andavar, like a piece of another planet fallen from the sky.