The Celestian Sacresants are drawn from the most skilled and devout of the Celestians, Sisters who have already proven themselves the equals of any warrior in their Order and are then entrusted with its highest honour: the protection of those who lead. Bound by sacred oath to their Canoness and the other masters of their convent, they form a living rampart between the enemy and the Sisterhood's most precious lives, and they are as much guardians of holy places as of holy persons.
Each Sacresant goes to war in heavy armour, bearing an anointed halberd and a broad, reinforced shield. Fighting shoulder to shoulder, they lock into a wall of blessed steel and consecrated plate against which the charges of heretics and xenos break and founder. Their discipline and skill are such that a mere handful can hold against many times their number, standing firm where a lesser guard would be swept aside, and driving the impure from shrines and reliquaries that must never be allowed to fall into unclean hands.
When no battle threatens their charges directly, the Sacresants do not idle. Many range across the Imperium upon their Order's business, hunting down lost relics, cleansing desecrated holy sites, and rooting out the sedition and heresy that fester in the Emperor's domains. Yet wherever their quests carry them, they return the instant the war-horns sound, resuming their vigil at their masters' side as though they had never left.