A Turaga Nui was a being which, legend stated, would be formed from the merging of the minds and bodies of six Turaga, creating a wise and powerful leader. The idea remained merely legend, as no Turaga were ever known to attempt this.1
Notes
It was indeed possible for the six Turaga to combine into the Turaga Nui.2, 3
Turaga Nui. A great sage and leader, created when all the Turaga join together as one.4