All living things are in possession of a soul, but the soul of Humans is unique, because it is able to persist after death (unlike the souls of animals or insects, which dissipate after death). Thus, every person experiences an afterlife, which lasts for an eternity after life itself. It is well known that the souls in the afterlife cannot experience the full breadth and beauty of life, but the afterlife has its own challenges and experiences. Indeed, souls are not immortal, and the afterlife, especially initially, is much removed from the paradise of safety and tranquility that some may seek out after their death.
After death, the soul remains attached to the now dead body. It must be freed from the corpse, and there are a few ways to achieve this. In the grasslands of the north, the bodies are left in the open steppe, to decompose and be devoured by carrion feeders. In the lakes and rivers, the bodies are placed upon a raft or boat, the construction of which depends on the wealth of that individual in life, and this vessel is burned. At the moment at which the skull is ruptured or burned through, the soul (which exists within the eyes) is able to escape the body. From here, it is able to begin the first phase of its journey - Swimming up the Great River.
Once the soul escapes, it must first reach the great river, or any tributary of it (in case the body receives a sky burial, this may take some days of flight, so a map or navigation aid is often left alongside the corpse). During this early phase, the great river serves as succor to the soul (replacing the body from which it is now freed), which must draw upon its energy to survive. Souls that are too far away begin to fade and disappear, this is why all peoples who live far from the great river cannot experience the afterlife, and this explains well their ineffectuality at all things, because they do not have the aid of their deceased ancestors in life (it is said that the borders of the ni.hɛ.syɥ and the ky.ɥt͡sæ.ʋkæ represent the furthest extent from which a particularly industrious soul may reach the Great River before fading away). If a soul is unable to reach the river in time and fades, this is a final and permanent death (indeed, burying a person alive, such that their body may decompose without leaving an escape route for the soul, is a surefire method to ensure such a permanent death. Some areas employ this as punishment, but all areas employ this as the method of disposal for the corpses of those born physically disabled or blind, because their deformed souls cannot be permitted to enter the afterlife). Since the rivers are the souls’ pathway, it is treated as a holy place and must be kept unspoiled (blood is, of course, acceptable).
After reaching the Great River, the soul must swim upriver, to reach the Island that is located in the Holy Lakes which form the source of the Great River. Souls, however, are not the only things swimming along the river. They are a tasty snack for the Salmon, so the souls must avoid them at any cost, often needing to work together to reach the end. Weak, treacherous, or socially inept souls will not be able to reach the end, and will instead be devoured by the Salmon. This will not destroy them - however, when the Wajahe eat the Salmon, they will destroy these inept souls. Eating Salmon is thus a virtuous action, as it ensures those ancestors that reach the second phase of the afterlife will provide sound and thoughtful counsel.
If a soul manages to escape the salmon and reach the Holy Lakes, they will find the island upon which the Children of Aiokkais hold court. Heshi will welcome them and set them free from their dependence on the Great River, allowing them to fly far and free. Souls now enter the second phase of the afterlife, during which they have many options. The highest honor, ascension to godhood, is granted to warriors of impressive renown that have accumulated a cult after their death by Heshi at this moment. They will become a patron god of whatever it is they adored in life, be it related to or separate from war, and use their divine powers to continue to inspire this in the living. Some other souls that were successful warriors may be chosen by one of the many Gods to join their retinue and serve as warriors. They train and guard their charge, in the event that Osaeuais renews the conflict in the stars (and during eclipses, which is when Osaeuais decides to temporarily test the defenses of the Gods). Souls can die during this charge, so while it is a great honor to join a retinue, it also exposes a soul to some degree of inevitable danger.
Those souls that were not successful warriors are allowed to choose their own path. Many, especially those with large and loving families, will stay on as a guiding light for their descendants, so long as their name is remembered. They appear in dreams and give wisdom when it is needed, helping the living choose a virtuous course of action. Others will perform acts of vengeance on their enemies that still live, or be a nuisance to various ungrateful descendants of their own. Nightmares are the wrath of such a soul - for while souls cannot make a direct physical impact on the world of the living, nightmares can cause one to sleep poorly and therefore be ineffectual in their life. Some souls will simply fly into the sky, and create their own little paradise in their minds, existing in a state of bliss that persists until the end of time. Finally, many will choose to live in the Court of the Gods, as citizens of that great and unseen city. Here, they take up all sorts of employment for their gods (if they wish employment as a means to pass the time). The most important service they perform is message delivery. If the gods have a message to send to the living, they no longer communicate it directly, as they did in the ancient days - after all, the Children of Aiokkais are lazy and not diligent, and this atmosphere of lethargy and relaxation affects the entire Court in all matters save that of vigilance against Osaeuais. Instead, the gods pick a soul who is willing, and direct them to an Oracle or other priest, who will relay these messages to the mortal world, and also bring back to that soul a message to relay back to the Gods. For the return message, some form of nourishment must be provided to the soul, to convince it to carry out this task.