The Grand Inquisitor was the head of the Church of God Awaiting's Office of the Inquisition as well as the leader of the Order of Schueler.
In the late 9th Century of God, the Grand Inquisitor was Zhaspahr Clyntahn, a member of the Group of Four and the main instigator of the Holy War on Charis and the Sword of Schueler. (OAR, MTAT)
In the Year of God 899, after Rhobair Duchairn rose to the Grand Vicarate, one of his first actions was to abolish the office of Grand Inquisitor and replace it with the Court of Inquisition, a committee of three vicars from the Orders of Langhorne, Bédard, and Pasquale. The Order of Schueler was specifically barred from having a seat. (AST)