Culexus CC

Lady Syncella moved so fast it seemed that slices of time fell out as she moved, jolting her from point to point with no visible movement in between. She handsprang over Ucalegon, landing behind him before he had powered the obsidian blade forward in a thrust. Ucalegon swivelled on his front foot, bringing the sword around in a wide arc, but Lady Syncella flipped over the blade.
The power knife in her hand was aimed at Ucalegon’s heart. It flickered forwards quicker than Ucalegon could react. Its power field spat blue sparks as the blade punched through the ceramite of Ucalegon’s breastplate and the inner armour of his fused ribcage.
It speared through his heart. He could feel it, feel the spasms of pain running down his limbs as his heart was sliced in two. He fell, coldness flooding through his body.
Syncella stepped over him, heading for the adjacent mountaintop of the Blood Eyrie.
...‘I left you a heart intact so the Imperium would not be robbed of such a warrior,’ she said. ‘I take it a man of honour would not stoop to scorn such a gift?’
...‘I tire of this!’ snapped Syncella. With a mental impulse she unfastened the clamps holding the collar around her neck.
The wave of cold, agonising hatred hit Ucalegon as hard as a gunshot. He fell back onto one knee. He had never felt anything like it before. Perhaps it was something like being plunged into ice-cold water, but the chill ran right through him, as if every cell of his body was immersed. And it had an emotion, as well. It was pure scorn, the emotion of someone who despised him made real, congealing into reality and encasing him from head to toe.
His internal organs felt frozen solid. He had barely enough control over his body to keep himself from toppling off the edge of the narrow bridge. This was not pain – a Space Marine knew pain well enough to understand it when it came, set it aside and keep fighting. This was something else. A violation of mind and body, an invisible hand that closed around his soul and crushed.

“Seventh Retribution”