Boneyard

The Boneyard (sometimes referred to as Purgatory) is the True Neutral plane in the Pathfinder Great Beyond cosmology. Ostensibly, its D&D analogue is Outlands, being the neutral plane with links to all other planes, with a gigantic spire as the main landmark. Functionally it shares more in common with the Fugue Plane of the Forgotten Realms campaign setting.

When a mortal dies, their "soul" appears in the Ethereal Plane, where it begins the journey out of the Inner Sphere to the Astral Plane, where they collect to form a literal river as they flow towards the outer planes. Occasionally souls will be intercepted by powerful entities such as Hags or Daemons, but for the most part the souls are protected by various Angels, Devils and Demons who have a vested interest in keeping the bulk of the flow moving to the correct destination.

The Boneyard is the terminus point of the river, where the incoming souls are sorted and judged by the Psychopomps who are overseen by the deity Pharasma. Eventually they are dispatched to their final destination in the Outer Sphere.

Locations

The Boneyard is a massive necropolis/city appearing like an immeasurably wide plate nestled on the top of a spire of Quintessence (fundamental substance formed out of alignment) that connects with the lawful plane of Axis below. The Spire is not infinite, unlike some other spires we know; but it remains impossibly tall and it is constantly growing at an unspecified rate. Legends differ on whether Pharasma created the spire, or whether it predated her, but it is certain that she knows the truth, but won't divulge it to anyone.

There is no night or day here, and the plane exists in a perpetual state of twilight. However the plane does have an analogue to a moon called Groetus; each time the Groetus passes it gets a little bit closer, as if hungrily looking to devour the souls on the dinner plate of the city. When it gets too close, Pharasma will throw up an atheist soul (who wouldn't be missed anyway) which Groetus finds distateful and will retreat back to the farthest reach of the sky once more.

The capital of the plane is Pharasma's Palace sits at the dead center and is the primary seat of Pharasma's power and the location of her own peitioners and servants. It is a magnificent building of white marble, standing in stark contrast to the gothic blackness of everything else. Souls that have unfinished business can make a petition to Pharasma to get their affairs in order before getting judged, though this typically requires some unusual circumstances before the petition gets granted and usually results in them going back to haunt somebody or sending a divine messenger to pass something on.

When they arrive, most souls will naturally gravitate towards a final destination without being coerced or require much input. These ones usually get shuffled to one of the Eight Courts, which correspond to each of the other outer planes. This is typically the last drop-off point before they depart for their afterlife and become petitioners of their respective plane. This is usually a very busy place, as despite the fact that the soul will have already been assigned, they still need collected by their appropriate agent. The court of Abaddon is the only quiet one out of the eight courts, because very few souls would willingly choose to go there and Daemons are banned from the Boneyards anyway. Souls that get directed here are typically out of necessity, because their divine patron makes their realm in Abaddon. Such is the antipathy towards daemons that Pharasma has authorised a single Devil and Demon to both stand here and actually warn the souls to go elsewhere. Souls that are truly neutral or worshiped Pharasma in life just go back to her palace as petitioners instead.

If a soul was conflicted between multiple alignments or has no divine patron to claim them, then begins the legal process of determining their fate. Such souls are presented at Pharasma's Court which are overseen by the various psychopomps, who analyse the deceased's life in detail, taking evidence from witnesses (sometimes mortals) and hearing arguments from various planar outsiders in order to determine the appropriate destination for them. If a soul is allowed the freedom to choose their afterlife (ie: they didn't commit crimes that dictate going to a lower plane, or weren't good enough to go to a good plane) they may alternatively decide to go to the Lake of Mortal Reflections and be drawn into the water and get reincarnated in mortal bodies. Though if the invitation is not accepted by the soul they are never given the opportunity a second time.

Immediately surrounding Pharasma's Court is the Graveyard of Souls which acts as the buffer zone between the bustle of the courts and the rest of the plane beyond. The graveyard is a literal memorial site to every person, race, and culture that ever existed and is therefore absolutely HUGE. Adamantly atheist souls (as in not just ambivalent or agnostic, but assuredly "anti-god") of insufficient relevance get abandoned here, as they are too difficult to judge and no agent will come to collect them. This makes the graveyard a sort of quarantine zone to keep them from influencing other souls. Atheists get to linger here forever and either go mad, or find acceptance in the new role as custodians of the graveyard... Else they get fed to Groetus on a bad day.

The edge of the city-plate is called Spires Edge (you will go splat if you jump). This area contains the City of Second Chances and is a shanty town made up of souls and petitioners called Asphodis, who were either too complicated to judge or had leanings that were insufficient to be assigned to an outer plane and chose to remain in the Boneyard without accepting reincarnation. It is also the dumping ground for souls that Pharasma knows will get resurrected, so they get deselected from the judging process because there would be no point in continuing. This is also the region of Boneyards most likely to encounter living mortals, typically adventurers looking to visit/rescue/reclaim a lost friend or loved one.

Inhabitants

Unlike every other plane in the Great Beyond, the Boneyard is almost exclusively the realm of a single divinity: Pharasma. Though Pharasma does not typically oversee every individual soul that arrives, and leaves the matter of sorting and judging them to the Psychopomps, only interceding during difficult cases or disputes where more than one god or realm might have a claim on the soul in question, but even then they typically get left to high-ranking Psychopomps to make such decisions.

Achaekek, the god of assassins, doesn't strictly keep a realm in Boneyards, but maintains his domain at the Axis side of the base of the Spire. Occasionally he will be contracted to take out a soul that steps out of line. Making his relationship with Pharasma a curious one.

As for the bulk of the population, the primary inhabitants are the Souls who by far are the numerous occupants, though by nature they are transient and don't stay for very long. Souls are incorporeal and unable to affect anything but are fully visible in the Boneyard. The fact that there are millions upon millions of them at any given time makes the task of sorting them out a long, time-consuming process, and trying to locate a specific soul in the crowd could take weeks.

Souls that have been judged and are allowed to remain in the Boneyard are Petitioners. They are combined with the quintessence that makes up the outer planes and given a physical body, such souls get their memories erased, but are permitted a new life and come back in two varieties:

Those who were loyal to Pharasma or were dedicated to the cause of neutrality come back as petitioners known as the Dead who appear as animated skeletons with sentience and free will that are immune to cold and have high resistance to bludgeoning. Some of the dead might get elevated to psychopomps themselves and given new duties, but many will live "normal" lives as clerks and bailiffs for the courtrooms until they fully align with the plane and reach their enlightenment, at which point they will merge with the plane itself and disappear.

Those petitioners that failed, either by being immature, self-absorbed, inconstant, or atheist are politely referred to as Asphodis. They appear as dried out corpses that continue flaking away over time, though many resort to flashy pigments and make-up to cover the decay. They are typically stubborn and resistant to change and take penalties to wisdom but have minor resistance to various energy sources. Asphodis are usually quite lacking in motivation and tend to mope around not doing anything productive. Though they are malleable to outside forces and can be given new purpose with sufficient coercion; sometimes they get manipulated by outsiders from other planes to act as intermediate agents to further their designs on the Boneyard despite Pharasma's enforced neutrality. With the right amount of cajoling, or if the circumstances allow, it is actually possible for Asphodis to make up their minds to move on to other planes and get on with a more meaningful afterlife, though that probably takes a sort of motivation that most would be lacking.