Staff of Artakha

The Staff of Artakha was an artifact that the Toa Nuva needed to recover in preparation for Mata Nui's awakening. It had once been kept in the Archives in Onu-Metru, but was stolen in a raid by the Dark Hunters.

The Nuva went to Odina to recover the Staff, only to find it was not there. Apparently they next traveled to Xia to find it.

Meanwhile in the Pit, the Makuta of Metru Nui and Toa Mahri Matoro were in the ruins of the inner Pit, where the Makuta showed Matoro the remains of Tuyet, a Toa banished to the Pit long before the Great Cataclysm. He demanded that Matoro use his Mask of Reanimation to bring Tuyet back to help him replicate the Nui Stone.

Matoro protested that it wouldn't work--she would have no mind or spirit when she was reanimated. But she did have fragments of the Nui Stone embedded in her armor, and Makuta told Matoro that with just the smallest fragment of the Nui Stone, he could create a new one using the Staff of Artakha.

Thus, the Staff's power is apparently being able to create something from just a fragment of it.