If any world is the antithesis of Terra it is Yasháin. Yashain is as magic-strong as Terra is weak.
It is believed that most of Hârn's gods, live here; the noticeable exception being Siem.
Yasháin is Kethîra's 'half-world', the realm of the dead. Hârnians believe that when they die they are reborn in Yasháin where everyone is immortal and from where, if they are lucky, they can find their way back.
Physical laws bear little relation to those of the other worlds, and Traditional notions of geography, weather and climate, eating and sleeping do not apply. Yasháin is a world that runs on magic.
Yasháinian kingdoms have gods and goddesses for monarchs; demons, demigods and dead heroes for earls, princes and barons. The personalities of rulers are not only indelibly stamped on the political and social framework, but also on the ecology, geography, geology and climate. When one crosses from one kingdom to another, one may well be crossing a definite line between lush forest and stark desert.
The kingdoms of Yasháin always seem to be at war: good against evil, and chaos against order.