Keystone

The Keystones were six pieces of a tablet detailing the way that the Great Spirit Mata Nui was to be awakened that was kept with Av-Matoran. They also acted as the key to disrupting the field around and opening the Codrex.

History
The Keystones were originally created by the Great Beings.

Over the years, the tablet was broken and the pieces were lost. According to what Kopaka could read after obtaining three of the pieces, the Keystone said that the secret to reviving Mata Nui was in the swamp below Karda Nui.

The Toa Nuva, while in Karda Nui, were able to retrieve the six Keystones, enter the Codrex, and use them to awaken Mata Nui.

Location
Below are the locations of the six pieces and current status of each piece.


 * 1) Formerly with Solek, now with the Phantoka Toa Nuva.
 * 2) Formerly with Kirop, now with the Phantoka Toa Nuva.
 * 3) Formerly stolen from the Av-Matoran by the Phantoka Makuta, now with the Phantoka Toa Nuva
 * 4) Formerly somewhere in the Swamp of Secrets, acquired by Gali and now with the Mistika Toa Nuva.
 * 5) Formerly with an unnamed Av-Matoran; now with the Mistika Toa Nuva.
 * 6) Formerly in Krika's base camp; now with the Mistika Toa Nuva.

Trivia

 * In the comics, the keystones are shown as six pieces of a square tablet that fit in the torso part of the picture of Mata Nui, but in the mini-movies, it is shown as six pieces of the entire picture, not just the torso. The latter version is confirmed canon.