Previously:
Steam
Salt
There is a theory which describes the elemental planes as a library of very big books - encyclopedias to be specific - written in matter-energy rather than words. They contain and constrain everything that the elements can and should be. It should then be no more surprising that lightning strikes across its plane without a sky to birth it or the earth to receive it than it is for the word fire written before you to not need to gobble up wood to remain there.
Of course: the librarians are dead or screaming and flaying each other for parchment and mold is spreading under the floorboards and the donour who the wing is named for is nowhere to be found and guerilla poets are breaking in after dark to inflict unseemly metaphors. This too is to be expected. For there is Order and there is Chaos and there is Chaos-from-Order and Order-from-Chaos.
It should then come as no surprise that there is more than just lightning to be found within the quasi-elemental plane of lightning.
Fickle As The Levin's Quick
But first the lightning alone.
There is air here, for the plane is of Air and the font of life. Even so, it's unwise to breath unmasked - it reeks of ozone, is adrift with arc-forged particulate, often super-heated.
There is light here, an endless stroboscopic flashing from all directions, the explosive intensity of micro-suns born in the natural fusion reactors of immense colliding magnetic fields.
There is noise too, a discordant and deafening orchestra: the languorous buzz of corposance, the pop-pop-pop of plasma, the roar of prayerfully-distant thunder.
Like the upper air or the open ocean, the plane is barren, but far from empty. Charged particles coalesce in the double-layered envelopes of ionized air, forming comets and cays, and fulgurite forests float through metastable and metastasizing plasmic braids. In the rare stable positions, like Lagrange points arranged by electromagnetism rather than gravity, entire planetoids can fall into shape.
And so there is life too, always life. The ecosystem is built off of electric bacteria - congealed into glowing mats, free-floating planktonic slime-molds, symbiotic with lichen, and void-filling membranous super-organisms. Aluminum-shelled crustaceans "swim" along magnetic currents, or anchor themselves in filter-feeding fields. Capacitorial zeppelinoids plunge between discharge zones to rid themselves of accumulated joules. There is a sort of hyperaccumulator vine which sprouts like tangled wires under the light of micro-suns and "harpoons" nearby soil-mass together into a garden for itself - though it can just as easily spear living creatures. Zeugalaks launch themselves across the bolt-stroked firmament, behirs stalk in the crevices of careening meteors, and umplebies brachiate through branching globes of glass and iron. The plasma itself sometimes seems to be alive.
Weapon Of The Gods
Plagues and floods and volcanic eruptions fall in and out of fashion among wrathful divinities - too slow, too indiscriminate, not flashy enough. Lightning remains the favourite for smitings.
The gods (those worth the title anyways) don't settle for terrestrial thunderbolts plucked from any old storm. They get the premium stuff, right from the source. They get them from the lightning elementals.
Lightning elementals are unlike others of their sort in that their natural form is unbound, a howling ecstasy that can't hold an identity or shape for more than a moment. For them to become stable beings they need to inhabit a substrate, conductive and computational. Since time immemorial their substrate of choice has been herds of creatures like sea angels made of super-conductive filaments, which they run on like software on a server. Each clan has their herd of their proprietary breed, and a god they are sworn to who they cultivate lightning for. Each clan conducts "cattle" raids on others and settles blood feuds with magnetohydrodynamic lances of molten metal. Each clan has its old alliances, which they moot with and dance in electric vortexes.
To Thunderous Applause
Sigil, that crown of the cosmos, is the center of the universe even now, shattered as it is. It was not always so - the Sigilites broke the old Order of things to forge their own. They threw angels down from the heavens and paraded through hells. The quasi-elemental plane of lightning they used for its energies, applied to industry and alchemicana, for magnetic mesmerism and revivification.
When Sigil fell its colonies stumbled bleary-eyed into freedom, and into deprivation. Severed from Sigil's portal-magics they had to fend for themselves in environments as hostile as any alien world. The copper-webbed satellites of the plane of lightning, hung like brutalized ornaments in the plane's stable points, faced three main problems: safety, material, and manpower.
Those left behind in the satellites were workers, exploited yet educated. Their management fled back to the imperial core. Their lives were dependent on complex systems requiring constant maintenance. Even in the power vacuum a tyrant couldn't rise - or rather tyranny was societal suicide - every hand and sort of expertise available was necessary for survival, and sabotage was devastatingly simple. What arose was at once egalitarian and totalitarian, an anarcho-Stalinist mesh of guilds and secret societies and work-crews, of strictly-enforced conformity and social contribution on the surface with a sea of hidden signs and conspiracies beneath. Sign languages were invented among them, which could be spoken even with lost fingers, to get around the omnipresent sound. Satellites linked into leagues for mutual defense and trade, specialized in the production of certain goods like weapons or vat-grown foodstuffs or metal-foam furniture, rocketing between each other in train-cars riding channels of ionized plasma.
These trains were also instrumental in harvesting the raw material the satellite-leagues were hungry for. Currents were charted, comets mapped, but this was not enough to exceed starveling rations. A great breakthrough came when it was realized that the herd-creatures of the lightning elementals could synthesize useful materials out of ambient clouds of particles. They no longer needed to scrape by for resources - only go to war with the weaponeers of the gods.
And so there is war. Fleets of trains rustle and whale and lobotomize herds Elementals retaliate with smashing violence, or infiltrate the satellites by insinuating themselves in organic nerves. Poetic telegraph-epics glorifying famed rustlers echo across the relay hubs. Prized "catte" are adorned with ribbons of magnetic gold alloys. Among the most vital industries now are those related to the appeasem*nt of the gods, the mass-manufacture of weapons-grade lightning to replace their lost suppliers, and of prayer wheels and idols and suchlike to assuage offenses. The war has gone on long enough now that it is no longer clearly cut between human and elemental - sub-factions on each side have seen it better fit their interests to work with each other against others of their own kind.
This war and attrition from the plane itself wear away at the population of the satellite-leagues, and their working-hours and cramped habitations don't lend themselves easily to reproduction. They found that to remain viable they had to manufacture manpower, or steal it.
From corpses jacked up with machinery and living electricity are made charmeats, the labouring dead. Some are fitted with explosives despite the danger to everything around them, so great is the fear that they might turn on their organic masters for their elemental enemies. Certainly they are no mindless zombies - mindlessness is uselessness to the engineering and repairs and so on they're applied to.
Strong storms on the prime material plane will manifest within them portals to the quasi-elemental plane of lightning. Special vessels are launched by the satellite-leagues through these portals, flying ships, which frantically track down towns and cities before the storm they arrived through dissipates. The ships drop burglars on bungee-cords, looking to snag as much loot and press-ganged personnel as possible in their limited time. For the inhabitants of these places these invasions can seem like hell come to earth, sky pirates with flesh riven by lichtenberg scars and eyes blanched by flash-cataracts diving in and twitching like they're blasted on stimulants, those they seize never seen again. In many grimoires the people of the quasi-elemental plane of lightning are described as a type of demon: stormwreckers, night rattlers.
In the rare instances that such a storm forms out of volcanic lightning these raids can devolve into brush fire wars with the Obsidian Menses of the plane of magma, who also emerge at these times, for different reasons.
Ride The Lightning, But Don't Lose Your Ticket
Besides the satellite-leagues and the lightning-clans, there are a number of other factions you might encounter on the quasi-elemental plane of lightning:
Freebooters: Life in the satellites is stifling, and so has its defectors and its exiles. Some satellites will kick out any obvious mutants, which are fairly common here due to barrages of charged particles and electric gene activation. These outsiders take shelter in hollowed-out comets, scrape bacterial slime off rocks to survive and pirate the train-caravans of the leagues, relying on risky, unstable and uncharted plasmic braids to evade capture and detection.
Thinking Machines: For about as long as it employed human labour in the plane, Sigil sought to replace it with a hardier, more obedient, and no less capable substitute. The solution it settled on was machines with crystal positronic brains, charged by anti-lightning upthrust from pockets of negative energy. The machines of course went rogue, stole the secrets of their replication and went to ground in corners of the plane where even its native life could scarcely tread. They are hunted still, even there, for the positrons within their brains are a precious commodity - a cancer-treatment among other things - often traded to the plane of radiance, though this provokes the celestial crocodiles of the infrared pits and their ultraviolet monopolies.
The Inquisition Electric: Mistrusted among the leagues even over their usual paranoia, yet indispensable. The I.E. are a remnant-organization of Sigil in the plane, true loyalists who have not abandoned their mission. They alone have the greatest understanding of the lightning elementals, of how to detect and disable their presence in living bodies, and of their internal politics. Their black spires meander the furthest from human-controlled territories of any vessels. Their mission is to disarm the gods, and this has gained them strange bedfellows.
