Isnalda Vassal of the Snake

Isnalda grew up in a Native American tribe in the dark Wild West; at a young age, she became a priestess of the Sand Devil—a demon worshipped by her people. Around the age of thirty, while wandering the desert, she was caught in a terrifying sandstorm and beheld the Sand Devil: a demonic serpent a hundred meters long. For some reason, the serpent chose her as its vassal, and Isnalda underwent a transformation that altered parts of her body and granted her immunity to the passage of time. She used her new power to help her tribe and its chief achieve success; however, the longer she lived, the less humanity remained within her. She resorted to horrific rituals, and when death came for the tribe, she sacrificed her own people without hesitation. Yet, even with the power gained from that sacrifice, she could not defeat death; forced to flee, she has wandered the desert's underground caverns ever since.