For those of you who have the book on the inner planes (particularly the 'evolution' entry), or are otherwise aware that the prime and the outer planes are increasingly invading the once-pure inner planes, or for anyone otherwise interested... I've been thinking.
What if the inner planes.. whether on their own, or by way of the forces that dwell there... or perhaps some effort from the rilmani, or any number of other possibilities.. started to 'strike back'.
Fire or Water, Positive or Negative, Para or Quasi, the elemental planes have been tainted too much, for too long. The genies were bad enough, so ancient that they have become natives, but the increasing invasions of celestials, fiends, and planars, and even the occassional prime, are taking hold of parts of the source of all, and spreading like viruses. A floating isle on the plane of air here, a citidel amidst ash there, and it's all becoming far too... organic.
Well, the inner planes can play hard ball too.
Elemental beings, whether pure, or formed like their foes (human-shaped, monster-shaped, etc), increase in numbers.
They gather. They plot. They plan.
A few small floating islands are found covered in ice, beneath which lies only ashes...
One-way portals are opened on the prime, forming vast, saline lakes and terrible volcanoes errupt from whence a civlization had arrisen.
Elemental gate towns are formed on the outlands devoted to the elements, forming a curious symmetry, with water as far from air as earth is from fire, etc etc etc.
Powerful elementals make their way to the outer planes, taking residence in the waters of oceanus, the furnaces of Gehenna, and the skies of the beastlands
Long ago, or so some sages say, the inner planes threw off the corrupted mire that became the prime, the ethereal a vapor trail left after so great an upheaval... the maggots did rise from this filth, and grow and evolve, sending their hopes and dreams to form the astral and the wheel. But the maggots and their dreams dared to seek their source, and trod upon the pure ground they had been so forcefully ejected from. Now, as it did before, the elements shall cleanse themselves, even if they have to consume the rest of the planes to do so.