This from the Artefacts and faction tech supplement:
The holiest of the Order's warriors go into battle dressed in animate suits of armor, technological wonders crafted by the factions' mythical animaturgs. This armor is the prime example of the Order's bionic proficiency, which is much more advanced than that of the other factions. A would-be user of an animate armor must undergo a long and rigorous training process. A complex relationship must be formed between the armor and its wearer. The armor must be harmonized with the wearer's physique and mind to be able to work. For some warriors, wearing the armor is like using a drug. Outside of its protective shell, they feel extremely vulnerable and weak, wanting nothing more than to return to the armor immediately. An animate suit of armor improves the strength and reflexes of the wearer, but its greatest advantage is its protective capabilities. The armor is adaptive beyond any other known technology and alters itself to withstand incoming attacks, becoming stronger as it is hit. Those in armed conflict with the Order try to counteract this by using experimental weaponry. The heretics on Zalos-B have so far been the most successful at this.