Brother Clarke.

As soon as Brother Clarke was released from the Grey Knights Sanctum on Titan he immediately grabbed the first transport to the front, he felt the need to purge in the Emperors name and Draigo had given him a few new ideas on how to do so.

Unfortunately for him the Litany of the Emperors Triumph happened to contain an entire Preceptory of Adepta Soritas from the Order of the Valorous Heart on their way towards one of the fiercest battles currently raging in the sector they were headed to and the traditional animosity between the Sisters and the Mechanicus was exacerbated the entire trip. This did not bother Brother Clarke excessively, it simply meant that he had to be more circumspect as he studied the Sisters equipment.

Upon exiting the warp the Sisters and Brother Clarke were hailed with much relief by the garrison of the world. The situation was stable, but brittle. Both sides had managed to dig in, with the lines stretching across nearly the entire upper continent of the planet. The PDF and Guard forces could hold the line, but they could not advance, not without losses that would critically weaken the line elsewhere and allow the forces of Chaos to again advance.
What they needed was for someone to break the line for them and then exploit the breakthrough. There was an Ultramarine successor chapter on the planet, but they had been bloodied badly helping the guard set up the defense line, they could not punch through and exploit the breakthrough as needed, they could only do one.

As the Generals, Chapter Master and Canoness Preceptor argued over how exactly to break the stalemate, Brother Clarke listened. As he listened he planned and eventually he spoke up. How he got them to listen was not known at the time but is now attributed to his Emperor granted powers. The plan would involve coordination between the Guard, Space Marines and the Soritas. This was doable. What nearly broke the plan was Brother Clarke’s need to put his hands on the Soritas and their divine war gear, as well as the Battle Barge that had brought the Marines to the planet. It is said that the Canoness Preceptor nearly had a screaming fit at Brother Clarkes request, but was eventually was brought around by the Lords General and the Chapter Master of the Space Marines.

It took two weeks of preparation, but after that time Brother Clarke had laid hands on every member of the Preceptory, from the Canoness herself to the lowest Battle Sister, as he adjusted their armor and weapons, as well as communing with the machine spirits of the Battle Barge so that they would grant them victory. In the end it was time, Brother Clarke said that all was ready and the forces were prepped. Brother Clarke himself would go into battle with the Canoness, to ensure that whatever happened to the Sisters would happen to him as well.

In the end Brother Clarkes effort proved to be exactly what the beleaguered planet needed. As the Guard waited behind their barricades they were treated to a sight that brought many to their knees in reverence to the Emperor.
The entire Preceptory was in Marine Drop Pods modified by Brother Clarke to allow such a thing, all guided by an extremely pleased Machine spirit. As they landed in near exact synchronicity, the pods burst open, disgorging the Adepta Soritas inside them.

And then the line burned

Brother Clarke had equipped every Sister and himself with a specially modified Melta gun, with nearly three times the range and twice the heat of a normal one. As all of the sisters triggered their weapons into the surrounding heretics and daemons, it is said that the very Immaterium itself was burned by the heat.

As one the Meltas stopped, preventing their energies from backfiring onto the Sisters. In that moment the fire cleared and the line was revealed. There was no more line; the Sisters had eradicated all trace of it in only thirty seconds. As all loyal servants of the Emperor surveyed the destruction, it is said that the Emperors Grace descended upon them en masse. It started as a roar from the Guard, then spread to the Custodes as they charged forward, finally reaching the Soritas as they moved to exploit the break they had created. All down the line the Emperor’s finest smote down the heretic and the daemon there was a glow, a glow of power, rage and belief. The Sisters had felt it before, they were renowned for such things, but this surrounded all of the Emperors children, down to the lowliest PDF cook who had seen the drop and extermination.

There was only one small detail that was different; this glow was tinged in blue.

A month after the drop the planet was nearly cleared and the Marines, Sisters and Brother Clarke were recalled so they could be redeployed on more important worlds. It was on the journey back that the Canoness Preceptor was visited by ever one of her surviving Sisters, asking to be made into a Sister Repentia for failing in their belief in the Emperor. The Canoness herself knew what they meant. For she had seen the blue glow of belief from her fellow Sisters, the glow the same color of Brother Clarke’s RIG, the glow she herself knew she had emitted.

Upon reaching Ophellia VII, the Orders home world, the entire Preceptory, all 874 surviving Sisters, fell to their knees in front of their Canoness Superior and begged to become Sisters Repentia for failing in their belief of the Emperor.

But they were denied.

Word of the Victory had spread as far as Holy Terra and the Abbess Sanctorum had heard the tales of victory, as well as of Brother Clarke and what he had caused. She had spoken with the Supreme Grand Master of the Grey Knights, as well as all in the system who knew of Brother Clarke, even those in the Mechanicus.

She had decreed that all of the Sisters were clean of sin, as Brother Clarke was so devoted to and gifted by the Emperor that it was near certain he had been granted his power directly and to believe in one such as him was to believe in the power of the Emperor.

The Colors of the Valorous heart are Black on Black, but in one Preceptory they allow a modification.
It is a small blue flame, placed down the crown of the helmet, in remembrance of those who saw what was wrought by Brother Clarke and the Emperor.

Reports that the Canoness and some of her members have requested Brother Clarke visit them at his convenience are unconfirmed at this time.