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. Once there, Onua Nuva encountered a Makuta by the name of Icarax who stole the staff.

Meanwhile in the Pit, Teridax and Toa Mahri Matoro were in the ruins of the inner Pit, where Teridax 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 Teridax told Matoro that with just the smallest fragment of the Nui Stone, he could create a new one using the Staff of Artakha.

Teridax tried to recreate the Nui Stone with the staff (given to him by Icarax), but an interruption by Brutaka ceased this action. Brutaka passed the staff off to Botar, who brought it to Daxia.

The Staff seems to have immense power. While in Daxia, the leader of the Order of Mata Nui places it in a pedestal and it healed the whole world. Everything as a result of the Great Cataclysm was healed. This great feat was described as only a fraction of the staff's power. Despite all of this great power, it wasn't able to heal the Universe Core the most damaged place in the world because it was too heavily shielded.

Thus, the Staff's power is apparently being able "heal" something no matter how damaged it is.