Dark Sun: The Scorched World of Athas
The Broken Builders are a cult that believe the only way to save Athas is to destroy it so it can be rebuilt. They originated as an elemental-worshiping cult in the city-state of Raam, but they have spread to all of the major city-states.
They try to do their best to ensure that the world becomes so utterly devastated that the elemental beings can fully shatter it in preparation for rebuilding Athas the way that it was mean to be. They actively encouraging defiling in order to speed up the process.