Usna Toakdee' was an extremely high ranking Elite at the time of the Human-Covenant War.
He was the head of the Council, Supreme Commander of all ground forces, and the religous leader of High Charity. He spoke for the Prophets in some occasions, hence his title. It may also be noted that he was the tallest elite ever seen by UNSC forces, standing a full 10'3".
Speaking of Halo, I've got a project in the works! If you've ever read the Halo book, Ghots of Onyx, then you'll get this. Im building Pegasi Delta. A 300esque battle that takes place with 300 SPARTAN III's against a Covenant refinery on the edge of UNSC space.
I expect the project as late as 3-4 months.