Cult Mechanicus Battle Congregation
The third army of Mechanicus forces alongside the Legiones Skitarii and Collegia Titanica, a typical Battle Congregation consists of a variety of forces from the myriad militant Mechanicum factions under the general command of a Tech-Priest Dominus. The makeup of the Congregation is heavily dependent on the strength of the Forge World and the Dominus' status in the labyrinthine hierarchy of the Mechanicum Priesthood. There are thousands of iterations.
Nonetheless, a typical Cult Mechanicus Battle Congregation will consist of Battle-Servitors (including Kataphrons) and forces from the Legio Cybernetica, Auxilia Myrmidon, Centurio Ordinatus, Electro-Priesthood, allied Knight Houses, and Ordo Reductor.