The Meaning of Life, the Universe, and Everything.
Is there a mod where comets/meteorites/tnt/lava/fire randomly rain from the sky at various angles? I think it might be fun to backup the map and flick the 'end of the world' switch. With variable speed of course, from "entire map is blasted down to the bedrock and covered in lava in 15 minutes" to "just patch up your roof occasionally"
Well you could do this with flaming arrows and TNT that would shoot from the sky. Should do all those except the lava will be tougher, but if you want lava falling from the sky that's already there in the nether.