Iterator
From Lexicanum
Imperial Iterators were public speakers, and masters of manipulating crowds and altering public opinion. The Emperor appointed them to spread the Imperial Truth among his people, for example the rejection of the religions and petty squabbling which had brought about the Age of Strife.
They were most prevalent among the fleets of the Great Crusade, where they would not only lecture and rally the Imperial troops and Astartes legions, but also educate the vanquished human civilisations on the values and virtues of the Imperium.
Iterators can be seen as the early precursors to both the Imperial Commissars and the Chaplains of the Space Marines after the Second Founding.
The most famous iterator of the Great Crusade was Primary Iterator Kyril Sindermann, who served aboard Horus' flagship the Vengeful Spirit at the head of the 63rd Expeditionary Fleet.
