The main exception to the inhospitability of the desert is the Purple Oasis, an impossibly large copse of opulent plantlife, ranging from pale blue to deep purple.
While undeniably magical in nature, no-one has been able to determine what caused it, or from which Sphere it draws its magic.
Pilgrims traditionally take no supplies, vowing to live off the sparse vegetation and lizards that inhabit it. It's a long, arduous trek, so many either give up or perish in their pursuit of the mythical goal of Nachi: to become a Conduit of two opposing Spheres.
An impossible cluster of alien plant life, the result of magic leaking into the world from one of the Spheres
Monoduga religion dedicated to becoming a conduit for two opposing Spheres