Beings in the Shadowend are composed of three parts: body, or corpus; mind, or spirit, called the essae; and soul, or vitae. The body, the physical aspect of a person, is exactly as one would expect. The mind, or essae is not just the conscious thoughts of a person but their essence; the "themness" of them. The soul, or vitae, is the animating force, the "aliveness".
Death is a discarding of the body and a migration of the soul and the spirit. Unless interrupted, these travel by various means and ways to Orod's realm, where the two are separated and the soul remains. The passage to his realm can take some time, and the dead are vulnerable during this time, but may also be recalled to life or contacted with relative ease.
Accounts have described the souls as candles, illuminated jars, or crystal stars; these are gathered and guarded by Orod until such time as Aeva, the Lady of Life, calls for them to return to the Wyrld. They are sometimes stolen by necromantic magic and used to animate undead constructs.
After travelling through Orod's realm, only the essae remain. Hitherto the dead appear as they did in life; now they assume somewhat lesser forms. Faithful dead are gathered by their deity or its servants; others are dispersed to the various petty realms, usually (but not always) under the care of Aeva or another protective divinity. Spirits attacked and killed in the petty realms reform whole and intact within a day. Spirits assigned to a realm reform there; manes generally reform in the realm that they died in, but occasionally in other random places (it makes no difference to them, really).
Lares: Good, virtuous, and beneficent spirits become lares. Lares resemble themselves in the fullest bloom of life and health, but viewed from behind are hollow, lacking their vitae. Despite this they are happy and content, dwelling in the petty realms much as they did while alive, but without disease, hunger, or woe. Some, the penates, find themselves returned to the Wyrld as guardian spirits of their family or clan; others, the einherjar, become crusaders against their foes, the baleful spirits of lemures and fiends.
Lemures: Malicious, cruel, or vengeful spirits become lemures, hollow waxen creatures with melted features. Faithful lemures are gathered by their patron deities; others are seized by whoever can take them and carried off. Some manage to return to the Wyrld and plague the living as undead, but most fall into the "care" of various fiends, where their experience is much as one would expect. Lemures universally hate and envy lares, and continually seek out ways to find and destroy them.
Manes: People who were neither particularly good nor evil become manes. Like lares, manes resemble their living form, except manes are hollow from the front, faceless and empty-torsoed. They instinctively keep this concealed from others, usually by turning their back, but occasionally by wearing concealing robes and masks. This affects their movement and perception not at all. They can be encountered almost anywhere among the petty planes, but generally lack motivation or desire. They may act much as they did in life, but without a care for success or failure. Others simply wander, acting out a deep-rooted dissatisfaction with their bland existence.
I don't usually crib wholesale from existing mythology (I prefer to steal it piecemeal), but this just clicked for me. I was thinking about the "petty realms" of the gods (and other beings), and specifically Broken Emr. As (technically) an "outer plane", it seemed some spirits of the dead might be found there, but Enyo doesn't care about the dead, so they had to be placed there by some other semi-random mechanism. (The whole "death is just like life" aspect of the Planescape Campaign Setting always REALLY bothered me.) Then I had an image of a spirit that you could only view from behind; a spirit lacking. Thus, manes. The tri-part identity is rooted back in college.
The many, many divinities of the Shadowend practically dictate that most people worship the gods collectively, favoring whichever is most applicable to the current endeavor. Thus, people with a patron deity are relatively rare. Most people are simply "one of the dead".
Aspects of the Shadowend afterlife are still in development; fiends and celestials are not evolved spirits, for instance, but some of the races that sprang up in the footsteps of the Elder Host when they first came into the Wyrld. Still, it ought to be possible for a particularly accomplished spirit to become something like that. Not sure that's a question that NEEDs to be answered anytime soon, though.