The isle of Therys began as a volcanic fortress for the phoenix Freydis during the Elemental Uprising, and was gifted to mortals by the Leviathan and Zaratan Lords after their combined efforts broke the mountain and buried the warmonger phoenix beneath the rubble and the waves. Major shrines to each of these elemental lords commemorate their valor and generosity, but the shrines have fallen into disrepair since travel within the island was restriced during the Serrnis occupation. In the days since the war's end, the roads have evidently only become more treacherous with attacks by monsters and highwaymen becoming increasingly commonplace.

Aside from its mythic origins, Therys holds historical significance as the birthplace of Morzem Hatzefal, the Tidal Sage, where he is regarded as a national hero. The island's relatively central location upon the Hasting Sea makes it a hub of trade, which makes it of particular interest to the Corvus Trading Company. Tensions between the island's Public Safety Commission, the Trading Company's local agents, and the continued presence of Serrnis Admiral VandelJaunt, brother-in-law to the late Governor General VandelJaunt, makes the region something of a powerderkeg as it struggles to recover from from years of conflict.

In ages past, Therys was known as the Accuser's Perch, a single great island crowned with a volcano which overlooked the straits of the same name. When a passing ship was carrying some dire sinner, a great phoenix would descend from the mountain and render judgement, sometimes absconding with the guilty sailor and sometimes incinerating ships whole.