When sacred mountain lakes began to freeze and thaw unpredictably due to spiritual imbalance caused by increasing Yeti expeditions, Tenzin Norgay performed an ancient water ritual seeking assistance from guardians across the world. The Taniwha, sensing the disturbance from its home in New Zealand's deepest waters, journeyed spiritually to the Himalayas, manifesting in the glacial lakes where it now serves as keeper of the Yeti's most sacred drinking spots and underwater sanctuaries.

The Taniwha Keeper possesses the ability to manipulate water in all its forms, creating dense protective mists that obscure sacred sites and controlling the freezing and thawing of critical mountain lakes where the Yeti drinks. It can shapeshift between serpentine and humanoid forms, allowing it to move undetected through narrow ice caves and appear as a mountain guide to turn away unwelcome explorers. Most remarkably, the Taniwha Keeper can create complex illusions on water surfaces that either mislead expedition teams or, for those deemed worthy, reveal cryptic clues about the mountain's true nature.

The Taniwha Keeper serves as both guardian and gatekeeper of the Yeti's aquatic territories, judging which explorers are worthy of glimpsing the truth by testing their respect for the mountain's waters, while maintaining the spiritual equilibrium of sacred lakes that would otherwise reveal too much about the ancient being's movements and rituals.