The Afterlife

-work in progress-
When a mortal dies, their soul doesn't automatically find its way to an outer plane. It wanders the Border Ethereal plane for a short time before meandering off into the deep ethereal. Some souls are aware of their death, others are not. While these souls are wandering the deep ethereal, they might create small dreamscape pocket dimensions without intending to, but these are effectively impossible to find intentionally. They are only known of because some extremely lucky planar wanderers have stumbled upon them and were able to return to speak of them. Luck is required simply to find one, because the deep ethereal is so vast and visual range is reduced to 30 ft in any direction, one could wander the deep ethereal for centuries without finding one. And those who did find one and returned were not able to ever find the same place again.
for the souls wandering the deep ethereal, they are simply dreaming as if asleep. Those who have been resurrected after death might have hazy dreamlike memories, but nothing more. Sages have found that at least some of the time those who still live actually project themselves into the deep ethereal while they dream during sleep; it's unknown if this is true for all dreamers or just some.
Eventually the wandering souls will find their way to the astral sea, and it's here where the 'afterlife' truly begins, for here is where they will meet the celestials, fiends, and all things in between. There are some exceptions, some souls who cling to the Material plane may haunt an area for decades or centuries, and may wander into the Shadowfell rather than the Astral Sea.
Where the Deep Ethereal becomes the Astral Sea, demons hunt souls to devour, celestials search for souls to bring to the Upper Planes, and Devils look to press souls into infernal service before demons take them. Souls instinctively flee from the Astral demons, but their flight takes them into the River Styx unless another spiritual being manages to catch them first. During this phase of their journey, souls can sometimes benefit from tools, weapons, keepsakes, and even money they were buried with. These things become real in the quasi-dream realms of the border between the Astral and Deep Ethereal plane. Money or treasures can help a soul pay a Yugoloth for passage to a safer place, or to defend against a demon or devil (in these cases, the money will actually disappear from their grave if it was still there). Keepsakes can guide them towards places they have an affinity towards, and weapons to help fight demons.
The manner in which one died and/or was buried can also make a difference. Those who die of old age surrounded by loved ones start closer to the upper planes, but those who die violent deaths start closer to the lower.
Souls that flee demons and enter the great River Styx begin a trek that can last eons. The River first appears in the 9 Hells, then wanders through the mid-lower planes, and finally enters the infinite layers of the Abyss. The unfortunate souls which are not picked up by devils, yugoloths, or other beings before they Abyss will eventually become food for demons, or become demons themselves. Tortured souls cause their bodies back on the Material plane to become undead, or if their body is destroyed will create Will-o-wisps.
There is a way to skip this process, but it is violent enough that it is rarely offered by anything but a Devil. One can sell their soul to a being of the outer planes who offers to buy. When the person dies, their soul skips the Ethereal and Astral phase of the afterlife and goes directly to their new owner. But the process creates such a violent ripple in the Ethereal plane that it will cause corpses to rise back on the material plane. Sometimes it is their own corpse, but if theirs is no longer viable, the negative energy will find it's way to another corpse. These undead created by the soul tearing of this process are stronger and more violent than the undead caused by long dead souls who eventually find themselves in a lower plane. Because of this, many of the deities of the upper planes are unwilling to use this process of bringing people into the afterlife because of the pain and violent deaths it can cause. They occasionally will make an exception for powerful heroes who could make effective celestials. Almost as rare as a celestial soul being sold are souls sold to demons. These are either nihilistic or insane people who sell their souls to a demon, knowing the demon will likely betray them. These are rare, but they do exist.

Type

Metaphysical, Supernatural