An Echelon is any member of the host which Eru The One has granted authority over each of his universes. One group of Echelons has been assigned per universe. The complete body of Echelons, which dwell within the Timeless Halls, are divided into the Upper and Lower Echelons. Echelons have a freewill, and several have been foolish enough to contend with the omnipotence of Eru; those who have include one of the Autoexecs and Belegur.

SOURCE(S): The Zork Chronicles, A History of Quendor, Zylon the Aged