Named after the theoretical progenitor material (which some archmasters have been rumored to possess), Apeiron are usually related to transition of the physical elements. Some Moros scholars shun the notion that the denizens of Stygia are the dead, and speculate that all Shades sprang from the grey lead of Stygia itself, transforming over time into diversified material forms representative of change.
Their appearance varies greatly, they could appear as gaseous clouds, as decomposing corpses or as alchemical elements.
Apeiron have great insight into alchemy and the relationships of various elements and are willing to advise their summoner in such processes. They are also skilled craftsmen, able to form or identify artifacts.