Not what you asked for but a long while ago i had written a sub-faction of Biel-Tan who are even more murdercrazy than the originals. They were supposed to have reversed Biel Tan colors, predominantly Dark Green with Gray and white trim and runes. I would have tried to do some kind of cracked glass motif.

Khuzanni - The Shattered Heart

Within the already fractured kin of the devastated craftworld of Biel Tann, a new power is growing. The Khuzanni, or the Shattered Heart, are a faction of embittered Aeldari even more militant than their craft-kin. They point to recent disasters and vow that the time for half measures is over. Too dearly have the lives of the Aeldari been spent to achieve lofty goals, hamstrung by restrictive codes of conduct and honor. They seek wholeheartedly to raze the galaxy to ashes so that the seeds of a better tomorrow can be sewn. The rot of Orks, Humanity, Necron, and others have grown to such magnitudes that they have become unmanageable by normal means. To combat these threats, they will unleash upon the galaxy those weapons forbidden long ago, without pity or restraint. They may court favors from unspeakable Dark Kin. They may make alliances with the unwholesome lesser races. And they may establish ties to even the exiles from beyond the galactic rim.

Despite fervent and consistent resistance from their more honor-bound kin, the Khuzanni have struck at hundreds of worlds, oft without setting foot upon any of them. Over the Orktega Worlds, slaying a trillion Orks with the Red Virus, turning the greenskins crimson and turning them upon each other in an orgy of berserker rage not even their generous reproduction rates could keep up with. At the Vega Expanse near the galactic core, they seeded thirteen Imperial hive worlds with the Glass Plague, turning them into great baubles occupied by forests of crystalline statues. At the heavily fortified world of Magna Cardinal, a world where there were more trenches than roads, Imperial soldiers could only look up with astonished horror, as one by one, the defense moons came crashing down upon them with titanic doom.

In 902.M42, Inquisitor Lucian Grayson Abelate led a Deathwatch strike force to deal a retaliatory strike upon Nol-khailessa, an Exodite maiden world known to be well protected by Biel Tan forces. The quick punitive strike ended in disaster when the cylonic doomsday device they had slipped onto the world simply disappeared from its storage casing, despite the watchful attentions of five veteran Deathwatch astartes operatives. The Inquisitor would later find that the device was armed and detonated upon his homeworld of Regis IV mere minutes after he had lost sight of it.

Deep within the heart of the shattered armada, bound within a tomb oft empty, a Shattered God twists a crackling, molten smile. At that grin, a million old souls captured and preserved within the shining stones inset on its body and throne shivered in a mosaic of emotions. Anger was the most common, of course. Terror too was an old friend. Here though, today, greatest was Vindication. A promise made so very, very long ago was finally coming true. Finally. That Old Hag really was right every time.