We all know that when Athasians die their souls, spirits, or whatever typically enters into the Gray and slowly deteriorates into oblivion. Novels and 2e source material has given us a brief and undetailed glimpse of spirits in the Gray, but what are peoples thoughts as to what else may transpire on this plane? While there, what might these disembodied souls experience as they wait to slip into nothingness?
Beyond that, in my game world I have described that every PC has multiple Undisolved Spirits following them around, the number increasing as they kill more and more creatures (obviously), so between that and the various other undead spirits that reside in the Gray it's my assumption that many gather in locations where there are large numbers of humanoid creatures on the material plane. The Gray surrounding/in a city is probably full of Undisolved Spirits and other incorporeal undead, trying to communicate or otherwise interact with the living but unable to. In any case, I think that all of your basic types of undead that reside on the Gray (as opposed to the more potent ones that manifest themselves much of the time) are too simplistic and tormented/pained by their undeath to really think or do anything other than follow around the living.
As a side-note to this in my game at least blink, etherealness and other similar spells, powers and effects that interact with the Gray/ethereal plane are bad news for PCs that try and use them for extended timeframes - a simple blink doesn't keep them in the Gray long enough for Undisolved Spirits and the like to physically attack them, but should they stick around for too long they'll get mobbed. Yet another reason why transportation-type spells aren't all that great on Athas.
Interesting take on the way the Gray and the souls trapped within interact with the material world, especially the spirits following your PCs. Reminds of miniture callers in the-darkness.
Similar, yes. When it comes to the PCs & settlements, it was really just a logical step to take after reading the Undisolved Spirit entry in TotD, plus the interactions we see between Tithian and these types of spirits in the PP. The train of thought went something like this:
1) Undisolved Spirits are created when an intelligent humanoid is killed violently or otherwise seriously wronged right before their death.
2) Creatures in the Gray can see 60 ft. into the material plane.
3) PCs tend to do a lot of killing...a good portion of which happens to be their fellow human(oids).
4) Areas where PCs are most likely to kill human(oids) are also areas where the PCs tend to repeatedly spend their time - city-states and other settlements, along the major trade roads, a bandit camp, etc.
5) If a PC kills someone and they become an Undisolved Spirit, and said spirit happens to notice the PC on the prime material, odds are it's going to try and get at the PC...unsuccessfully, of course, but it'd still try.
6) If the PCs are using normal forms of travel, or are teleporting a lot but tend to return to the same locations ("bases of operations") then the spirits would know where to congregate in order to be as close as possible to the PC, as often as possible.
7) If this sort of chain of events is occurring for PCs, then it's probably also occurring for others who kill on a regular basis - the SK's, templars, etc...all of which spend nearly all of their time in the same general location.
8) If Undisolved Spirits congregate where they're most likely to find those that "wronged" them, then they will logically congregate in the same places that the living will.
...and thus my theory that the Gray reflects the prime material in both a "location" sense (i.e. that it's like like ethereal, with "physical" features that are similar to those at the same location on the material plane) as well as in a "living" sense (i.e. where there are groups of intelligent creatures on the material plane, there will similarly be groups of undead on the Gray-side of the same location).
Souls that wander around the Gray eventually dissolve down into a consciousless state, becoming part of the Gray itself.... Graystuff if you will.
From there, parts of the Gray "bleed off" into other planes, being used to create new lives... be it demi-human, monster or even plant.
Occasionally, a spirit that has not broken down completely will be bled off, resulting in what you'd call a reincarnation... a being with a few incredibly vague memories of a previous life, usually triggered by seeing something from said previous life.
While this is happening though, the spirits of a the Gray wander about in a dazed stupor, their minds unable to comprehend their situation, usually re-living in their minds strong emotional events that occured in life.
Some powerful spirits are able to control various parts of the Gray, usually spirits of powerful spellcasters or psionicists. Such areas appear to be life-like locations, such as old palaces, grand cities, druid groves, the Pristine Tower, a simple home or even a patch of desert... depending on who's powerful will imagined it.
The places are almost completely life-like, and indeed it is impossible to tell the difference, aside from a Gray mist or fog that permeates even interior locations, and a palpable feeling that something is missing.
The spirits of said-constructs are usually powerful spellcasters or Psionicists, but occasionally will be lorded over by an exceptionally strong-willed being. Either way, such beings are near-impossibly disciplined and focused in order to keep their minds and spirits from dissolving away to nothing.
Not all strong-willed spirits lord over such constructs, as a few lack that much willpower, but such spirits without a construct wander about the Gray, undoubtebly attracting unwanted attentions. Such spirits number only in the lower-hundreds at most, and even then, they decay over the ages.
However, a few spirits from recent days (The last thousand or so years) have been able to take another step forward, and actually grant other spirits their minds and wills back.
If strong-willed spirits were an exceptional rarity, these beings are exceptions to the exceptions.
They are able to grant a small portion of their own spirit-force to another lesser spirit, allowing it to become coherent. However, in exchange, such spirits are usually forced into slavery without any hope of escape, as such a gift can be relinquished as well.
These exceptionally powerful spirits, as you may have already guessed, are usually of former Sorceror Kings. They search, hopelessly, for ways back to the lands of the living, fighting one-another for the only resource available: spirits.
Such beings are forever doomed to continue a never-ending war, with those beneath them doomed to everlasting slavery or face oblivion.
However, even these powerful spirits will lose their focus in this never-ending cycle, and they too will dissolve down into the same material as their prison... inevitably, these spirits will crumble to nothing, and others will take their places, and the cycle will begin again.
And that's about it.