Source: Bestiary 6, pg(s). 220-221
In their true form, olethroses appear as moth-winged women clad in a spiral mask and a white, silken gown glimmering with tiny bronze mirrors. A typical olethros stands five feet tall and weighs 100 pounds, while olethros mothers are much taller, commonly reaching nearly eight feet in height and 250 pounds in weight. Normal olethroses always wield silkbows built from diaphanous strands of cloth and silk that only function for them, though olethros mothers can use different weapons. To a mortal, an olethros might disguise of a wise midwife or former mentor.
Olethroses move among mortals in disguise, watching the strands of fate interweave and acting to promote their view of fate and stymie those who fight against fate's flow.
Olethroses hate undead like all psychopomps, but rarely fight them, focusing their enmity on the sahkils and often hunting them on the Ethereal Plane, ostensibly because one of the first sahkil tormentors was originally a traitorous olethros.
Unlike most other psychopomps, olethroses are not forged from petitioners in the Boneyard, but are born from other olethroses via parthenogenesis. They claim that new olethroses are born when a new branch of fate forks off, and the newborns are destined to study and nurture that branch and the lineages involved.
Olethroses stand outside the normal psychopomp hierarchy, answering only to Pharasma herself or the psychopomp ushers. They see themselves as rivals to norns and enemies to lipika aeons: olethroses disapprove of lipikas' manipulation of the cycle of life for some alien sense of karma and occasionally get into shadow wars against them that might span dynasties. Morrignas respect them, nosois consider them bossy, and yamarajes respect their independence but sometimes request one as a witness or advocate during a difficult case. Olethroses never refuse these requisitions, but do not like to be assigned such tasks too frequently.
Very few olethroses are capable of becoming pregnant; those that do grow massively in power and become known as olethros mothers. Olethros mothers are far less common than standard olethroses and much more likely to have subsequent daughters than an ordinary olethros is to have a first daughter. Each mother develops her own area of expertise where even yamarajes defer to her. The most powerful olethros mothers are advisers and near peers of the psychopomp ushers themselves.