Toa Mata was the name given to the six Toa who appeared on the island of Mata Nui and battled to save it from Makuta. The Toa Mata were Tahu, Pohatu, Onua, Lewa, Kopaka, and Gali. They were transformed into Toa Nuva by immersion in energized protodermis.
Six stars above Mata Nui were believed to be the spirit stars representing the Toa Mata.
Members of the Order of Mata Nui had familiar knowledge of the Toa Mata and their accomplishments.
Unlike all other Toa known to the Order of Mata Nui, the Toa Mata came into being as Toa already; they were never Matoran and never transformed into Toa.
There was a place in the Coliseum that no one had ever seen from which one could fake the signal that would launch the Toa Mata's canisters.
The Toa Mata were the team of Toa destined one day to reawaken the Great Spirit Mata Nui. Led by Tahu, they were named the "Toa Mata" by the Matoran inhabitants of Mata Nui. During their year on Mata Nui, they battled Rahi beasts, the Bohrok, the Bohrok-Kal, the Rahkshi, and Makuta Teridax himself.
Of all the Toa, only Tahu Nuva had clear memories of their last visit to Karda Nui, when he tricked the others into remaining in the Codrex for 100,000 years. It was not something he was proud of, although he knew it had to be done. Had the Toa been out adventuring during that time and one of them had been killed, they might never have achieved their destiny and awakened Mata Nui.
It is possible that the design of the Toa Mata was partly based on the design of Mata Nui.[7, 8] Conversely, Mata Nui's form may have been modeled after theirs, since the Toa Mata were created before his completion.
Wherever Mata Nui should have fallen asleep, it was always assumed that Mata Nui would be pulled in to some sort of gravity well, like a planet, so the Toa Mata could then be launched onto his face.
The Toa Mata served as a failsafe. The knowledge that there were such failsafes in the Matoran universe was not a huge secret, but over time that knowledge devolved into being seen as prophecy, which is how the Turaga knew about them.
The destiny of the Toa was to free the Matoran from Makuta.