The Anchorite: a reformed Word Bearer and one of the few living instances of someone turning to Chaos and then turning back. He was disillusioned with the Primordial Truth during the Battle of Calth, when he realized that the humbling of Monarchia had only made his legion stronger, they had come back to humble the Ultramarines because of that strength, which would make the 13th legion stronger and lead to retaliation in turn, and so on, in an endless cycle of revenge. Realizing how futile the Calth campaign would be and unable to change anything, he decided to surrender and stop his part in the meaningless fighting. Surprisingly, he was spared by Guilliman. He was brought to the Black Cells on Terra in and began a long contemplation, where he re-embraced the Lectitio Divinitatus, which he had memorized in his youth. Later, he was entrusted to the Ecclesiarchy to keep imprisoned and hidden, where he was a substantial influence on the development of the Imperial Cult by imparting the Lectitio Divinitatus' writings by word of mouth. He gave up his name some time in here, and referred to himself only by the role he took on; an anchorite, "The one who has faith, the one who locks himself away from the world and keeps himself away from them to become closer to God."
He attempted suicide some time in his seclusion out of shame at how his Legion had ruined everything (on the Cardinal World Almace) and was interred in a Contemptor Dreadnought. His existence was revealed during the Indomitus Crusade, when the Word Bearers tried to 'reclaim their lost brother', and when he finally took the field against them he manifested the powers of a Living Saint.
The Anchorite faced the wall of metal and stone, its giant digit scratched and scraped until the words came to light. Like archaeoseekers of old the words seemed to appear from the metal, like dust brushed away to reveal treasure below. He stood and scraped, until finally the sentence was finished.
“I admire such dedication.” The voice came from behind him and the machine flinched. The voice was calm, stately, patrician. It had been thousands upon thousands of years since he heard it but his body within the metal shell reacted like it did when it was not encased in such a chassis. He could feel his hearts shiver then, and he felt them now.
The machine turned with a soft whine. His body was as well kept as the giant automata of the Mechanicus, but age and war always left marks that could not be erased. In fact the Anchorite demanded that the latest scars made from Bolter and blade to be left unfixed, physical memories of wayward brothers.
Though he towered over the speaker the Anchorite felt small in his presence. The gene fathers always towered over their sons and the effect was always there, even when a Primarch met those not of his own blood. “Thank you...Lord Guilliman.”
Roboute Guilliman, the Avenging Son, Lord of the 13th, nodded in reply. Keen eyes swept up and down the war ravaged grey shell. “I heard you helped defend the world.”
“No...I did not.”
A thin brow rose. “No?”
“No. I fought brothers that have lost their way, I fought those that have fallen, and to repay a debt.”
Guilliman nodded, almost shrugged. “Fair. Yet one could say all of that is true. Despite the reason, you still accomplished the deed.”
The Anchorite did not reply for long moments, his sensors watched the Primarch pace the room, reading the inscriptions that the dreadnought had inscribed for many years. “Have you come to relieve me of my debt? Have I filled my purpose?”
“Have you done that?” Guilliman asked, a keen blue eyes spitting the machine as sure as a tracking light.
“Perhaps,” Guilliman agreed. “Yet no, that was not the purpose here. Imagine my surprise to hear of your continued presence here.”
The dreadnought rumbled, a deep house like the cooking of a large caliber weapon. “I cannot imagine you being surprised,” the Anchorite snorted.
“Many things do,” Guilliman said softly, almost too softly for the aural sensors to detect. “You ask if your debt is paid, it is not.” His voice rose. “I have use for you yet.”
The Anchorite bowed slightly, gears grinding. “Command, and I will do.” He watched as the Primarch held a data spike in one hand. The large dreadnought claw picked up the delicate thing and slotted it into an open slot. As data pooled through the sensor net the Anchorite laughed truly now. “Surely you must be joking.”
Guilliman was unmoved by the loud laughter. “Never was good with humor, not even when I was younger. Back in brighter times.”
“No one would accept this,” the Anchorite protested. “Not one. All would find this mad. I find this mad. Who would trust a traitor with this sort of power?”
Guilliman extended a cobalt encased finger and tapped the Anchorite’s chest plate. It rang, like a bell. “I do. I trust you. I trusted you then, I trust you now. I have need for good men, ones who can fight, lead, inspire. You did not have to fight but you did. You did not have to resist but you did. You may not want to lead,” the Primarch gestured around at the walls covered in writing, “you will.”
The Anchorite stared. If he still had a jaw it would be gaped open. “I...do not know.”
Guilliman turned to leave. “I do. You will. This is my command. This is your debt. It will be paid.”
“To take these new Primaris, to lead them...” The data flowed into the Anchorite’s mem-banks. Numbers of troops, of a ship, equipment, logistical data. “To the other side of the the Maledictum?”
“Indeed.” Guilliman walked away and his steps echoed with surety. “To bring message to the Imperium Nihlius. That they are not alone.” On the threshold he looked back at the Anchorite and the machine almost fell to his knees. “It is time for the Heralds to return, and bring illumination to the dark.”