Strap in You know the tour.
Long ago. Just after the Great battle. Several Matorans gathered around the crumpeling bodies of their gods... one amonst them picked up the legendary block of power.
With these, He forged equipment of great such as the first masks of power.
He gathered a small unit of Freinds. They acting for the greater good of the islands inhabbitnts.
They would be the first Toa...
Knowing that they could not protect the island forever with these blessings of their gods they would pass on their equipment to pass on the power of the Toa... the essense of their gods.
So that other could take up the mandle.
Check the other out if you don't have I am