It's funny, Fleugs and I have been hashing something out like this on IRC and in-game on BT for a week now. The idea is that it's the worship of very old gods; ones that thrive where humans don't. That means rogue regions in-game, so the organizing principle is basically "burn most, but not all, of it down!". Theologically, the deity being worshipped is a feminine, darker nature/mother goddess. Her children are the elements, which Fleugs and I have taken to mean elemental daimons. Since the daimons love people treats, ritual means sacrifices to the mother by "feeding" her children. That's being burned alive for fire, drowned for water, buried alive for earth, and—this one belongs to Fleugs—being launched off of cliffs with trebuchets for air.
I'm pretty sure we're moving forward with it in Rio. Fleugs has already done some RP. If anyone is interested, come find us. 
Gonna do one more now. Alive burial hasn't been done yet. And also, no trebucheting. I was thinking of hurling burning victims to the walls of an Enweilian city? I already threw a whore off a cliff. *Splash*
