Comprised of the scattered remains of various cohorts most of which being cohorts which had divided against each-other in the face of the Mechanicus civil war, and Fabricator-General Kelbor-Hal's joining Horus against the Emperor in the Horus Heresy. The Erranigos Vindicata Cohort was swiftly brought together with the intention to have the Cohort swear to join the loyalist forces in tracking down and slaughtering the remaining traitors. However, the Cohort was forged and battle ready nearly too late to join the loyalists in their pursuit of the heretics, as bureaucracy in the reorganizing Adeptus Mechanicus would stall their official reformation, and thus vows of the Myrmidons were changed to the elimination of any and all heretical forces.