Saint Celestine is a revered Living Saint of the Adepta Sororitas's Order of Our Martyred Lady. She was believed slain during a campaign against the Renegade Warmaster of Forrax, but has returned at various times since to rescue Imperial forces in danger of being destroyed by the enemies of the God-Emperor.
Very little is known of the life of the Battle-Sister known as Celestine before she was declared a Living Saint, other than that she was once a Sister Repentia of the order of Our Martyred Lady that fought alongside the multitudes of Imperial faithful during the protracted war against the Heretics of the Palatine Schism. Celestine was at the forefront of the first wave of the deadliest fighting and was thought to have been killed in battle before the capital city of the planet Eurytion. She fell that day, alongside every other Repentia, but despite her defeat, it was said that she accounted for the deaths of over one hundred Schismatics during the assault. As Celestine's body was reclaimed by her Sisters and set amongst the honoured dead, they saw that life still lingered within her, and the light of one touched by the divine will of the Emperor glowed within her eyes. Cleansing her body of the blood and filth of battle, the Sisters were astonished to find that her body lay flawless before them. The next day the assault resumed, with Celestine at the head of the Imperial forces. The Heretics fell within hours as Celestine wreaked her bloody vengeance. She was hailed as the Crusade's sacred figurehead as the entire sector was eventually scoured of Schismatics and others deemed unworthy of existing within the realm of the Emperor of Mankind.
The Crusade's leader, Lord Militant Ansgar, believed the Crusade would reach its conclusion on the capital world of the Palatine Sector, but Celestine insisted upon first liberating the small backwater planet of Sanctus Lys. Unknown to all but her, that world was home to the Shrine of Saint Katherine of the Order of the Fiery Heart, a holy place visited by that Living Saint in secret just before her death. Celestine's followers found a broken altar amidst some ruins and were ordered by Celestine to remove it. Beneath the shattered remains, a hidden crypt was found. Barring any from following her, Celestine descended the dusty steps that none had trodden in millennia. As the dawn of first light broke above the ruined shrine, Celestine rose from the tomb, borne aloft on a column of divine radiance and attended by cherubs and doves. She was now clad in a suit of shining golden Power Armour, and wielded a vibrant blade that none could look upon -- the Ardent Blade.
After her apotheosis, Celestine was declared a Living Saint by Lord Ansgar and a conclave of Thorian Ecclesiarchy priests shortly thereafter. Saint Celestine was hailed as the "Hieromartyr of the Palatine Crusade", and praised for despatching thousands of Heretics at the vanguard of the Imperial forces as she prosecuted numerous later Wars of Faith. Her presence invested the faithful with an unprecedented fervour, and hundreds of thousands of Heretics met a fiery end at the hands of her armies. Many were fearful of her presence, for to stand before her was to submit to the judgment of one so pure in the eyes of the God-Emperor that her example could never be emulated. Her influence upon the Adepta Sororitas, for whom she became the focus of total veneration, was miraculous; she was a Living Saint, whom the Sisters would follow even to the very center of the Eye of Terror.
Alas, Saint Celestine was lost to the Imperium whilst fighting the Renegade Warmaster of Forrax. When the lunatic Warmaster triggered the meltdown of the ancient atomic pile at the heart of his fortress, an area many miles across was blasted to ash. Many believed she perished during her moment of triumph, yet none survived to give true account of the battle's conclusion. The mighty Tower of Heroes upon sacred Terra tolled once to proclaim her loss to the faithful, a billion souls pausing in their toil and looking towards the Emperor's Imperial Palace, united in their grief for the fallen heroine of Mankind. But the Sororitas, at prayer within the halls of the Convent Prioris, were gladdened by the mournful peal, for they knew that had she fallen, Celestine was now sitting joyfully at the right hand of the Emperor.
There are those amongst the faithful whom believe that Saint Celestine did not die all those centuries ago fighting against the Warmaster of Forrax, for there have been some confirmed sightings of the Living Saint throughout the ages. In one noticeable incident, during the Promethean War in 980.M41, the Order of the Ebon Chalice was sent to reinforce the Space Marines of the Salamanders Chapter in a brutal urban war against the dread Chaos Space Marines of the Black Legion on the world of Heletine. The enemy was put to the torch as dozens of Immolators and Land Raider Redeemers burned a path through the war-torn cities. Despite the strength of their forces, the advance was halted when Lord Gralastyx -- the Daemon Prince leading the Forces of Chaos -- unleashed a swarm of Possessed Chaos Space Marines. As the frenzied Chaotic horde ripped through the Imperial ranks, Battle-Sisters and Space Marines alike fought back-to-back, their Bolters and Flamers blazing away as every warrior endeavoured to sell their life dearly. However, the allied forces were saved by the miraculous intervention of Saint Celestine, as she appeared out of nowhere, falling upon the Chaos horde like an avenging angel. The Living Saint carved a path through the horde towards Lord Gralastyx, before plunging her blade through his black heart. With the death of Gralastyx, the Chaotic horde was destroyed, but of Saint Celestine there was no sign, for she had vanished as mysteriously as she appeared.
- Codex: Witch Hunters (3rd Edition), p. 47