Dalon is on its most basic level the name for the moon. More specifically, it’s the name of the realm that lies upon the moon. Dalon, meaning the Choosing Grounds, is the home of the goddess Geila and the realm of the dead.
In the early days of the world, Geila departed from the earthly realms out of contempt for her neighbors. She took up with her a turtle, which she turned into the realm of Dalon. The turtle now swims over the world, constantly rolling about with Geila residing inside of it. The new moon is the turle’s underbelly while the full moon is the polished surface of its shell.
Dalon is known as the realm of the dead, but it is not the final resting place of the dead, nor do the dead immediately awaken upon it. The dead are conscious exactly when they leave their bodies, and they in turn wander until they are found by a mountain lion. Mountain Lions, being the favored animal of Geila and thus her chosen psychopomps (ferriers of the dead), lead the dead to mountain tops where they then are taken up to the moon. On the moon, Geila then judges the dead and informs them of what they might be reincarnated as. The spirit is then given a full month to decide from the options it is given and then allowed to depart into its new life.
This cycle lines up very specifically with the lunar month. The new moon, Dalon’s underbelly, is the entrance to the realm and thus spirits are allowed to ascend to the realm of Dalon when the dark side of the moon is visible. In turn, the light side of the moon, Dalon’s shell, is when spirits may descend to their next life in the cycle. As a result, the full moon is both loved and feared for bringing life into the world while simultaneously trapping ghosts upon the earth.
Needless to say, Dalon did not originate as the realm of the dead. It took on this role in the aftermath of Reho tearing a hole in the dome of the world. After the Wasp Mother and Iwau crawled out of the rift, water and otherworldly energy also was pouring through. Reho was naturally charged with plugging up the hole, which he did remarkably well. However, there did come a time shortly afterward that the gods realized an issue with this plan. There was now far more water and energy in the world than before, too much for it to support. Therefore, Geila took it upon herself to carry the rift around with her in the turtle of the moon. She would open the rift at times to either force the water on the earth to return to the realms beyond or to allow more water to return as rain when she took too much.
This cycle of water eventually drew ghosts to her realm, who’s vaporous bodies often got taken along for the ride. After going through the ordeal for enough time, Geila decided to just become the goddess of death and take care of all these things formally.
Finally, it is of note that, though Geila does pass judgement and dole out new lives to spirits accordingly, there are no forms of reincarnation that are thought to be intrinsically bad. The manner in which Geila judges the deeds of a person’s life is by cataloguing them as being of one of the five elements: water, wood, fire, earth, and metal. A human spirit who is particularly strong in one element risks imbalance and harm to the world around it, so Geila selects option for the soul that would encourage taking on qualities of another element. I.e. someone who is highly excitable and frivolous (both seen as belonging to the wood element) might be reincarnated into a family of merchants or banker (both professions of the metal element) in order to teach discipline and self-control.