Athreos's Influence

Most mortals focus on the River Guide's role in their own deaths. Countless mortal superstitions prescribe ways to garner Athreos's favor, but all Athreos demands of those he transports is payment: a single coin of any minting or value. The River Guide has an expansive definition of what constitutes a coin, from actual stamped currency and jewelry to shiny beads or opalescent shells. Ultimately, he seems most concerned with whether a mortal has prepared for death, keeping payment ready out of respect and as a personal memento mori. Those whose bodies are burned, buried, or otherwise disposed of along with valuables deliberately intended for the River Guide discover that they can make use of such items when trading for Athreos's services. Spirits that reach the shores of the Tartyx River unprepared, though, risk being stranded, as Athreos refuses to ferry those who can't pay.
Athreos is also invoked as the god of passage, as well as the deity with dominion over borders, boundaries, and that which is "neither." Those who undertake journeys, especially dangerous ones, often drop a coin into a fountain or a body of water in apotropaic acknowledgment of the River Guide. Bridges and borders are also places where Athreos is commonly remembered, with many such sites being marked by motifs of rivers or spirits. Additionally, phenomena that are neither one thing nor another, defying simple classification, are often considered to be within Athreos's province—most notably the state between life and death, but also echoes, phantom sensations, and the feeling of déjà vu.

Athreos's Goals

Athreos endlessly works to maintain the balance between Nyx, the Underworld, and the lands of the living. The River Guide sees himself as a servant of the mortal world and knows nothing of the glamor, honor, or mystery mortals often ascribe such to him. Rather, he does what must be done, and should some cosmological condition fall out of sorts, the River Guide and his servants work with silent efficiency to restore balance.

Divine Relationships

Athreos cares little for the dealings of the other gods. As long as other deities don't impinge on the border between life and death, either by overstepping their bounds or by trying to draw the dead back into life, the River Guide has little to do with them. More than once, this isolation has put Athreos in silent conflict with Heliod and Erebos, both of whom subtly resent Athreos for limiting how much each can meddle in the other's realm. At the same time, the River Guide's role as a buffer between the two vindictive gods actively prevents their grudges from exploding into divine warfare.
Thassa bears a chilly respect for Athreos. In a time before reckoning, boundaries divided the god of the sea's dominion from the Tartyx River. Though the god of the sea quietly resents sharing even a drop of water, she considers the River Guide to be a quiet, unobtrusive trespasser on her favored element and keeps her distance. Were her respect to wane, though, Thassa would eagerly vie to control the Rivers That Ring the World.