According to Tuyet, there was a known legend about the Nui Stone. Where an ordinary Toa stone was merely a passive receptacle for Toa energy, the Nui Stone was active. It did not wait for a Toa to give it his or her energy – it took it. Once activated, it would absorb minute amounts of energy from any Toa within a 3,000 kio radius, so slowly and surely that it would not be noticed until it was too late. Then that energy could be absorbed by a living being, possibly resulting in one being with the power of dozens, maybe hundreds of Toa, or more. Such an item was potentially dangerous. The makers of the Nui Stone realized the risks; they made only one and vowed to destroy it. Before they could do so, it was stolen – no one knew by whom. It was passed from hand to hand for millennia, no one ever realizing what it was or what it could do, only that it was powerful, and so valuable.
The Nui Stone was a glowing red stone. Because it was full of energy, it gave off heat. When Tuyet grasped it in her hand and tapped its power, it began to crackle, and a nimbus of crimson energy surrounded her. Her power increased rapidly. When Tuyet dropped the stone and lost contact with it, her new powers abruptly vanished, and the sudden loss of power stunned her. The stone hit the ground and splintered into a billion fragments, whose red glow flared and then faded for good. With the destruction of the stone, the red glow faded around Tuyet as well.
In the alternate universe of the Toa Empire, when Tuyet tapped into the Nui Stone, it gave her the power of maybe 100 Toa. Tuyet claimed to have hundreds of times the power of Takanuva.