"Can you hear the sweet prelude of our Lord? Can you hear how its cadences purify the soul, flaying skin from bone to lay bare the dark bosom beneath? Can you feel each motif as it touches the heart, rupturing veins, bursting through in a crescendo of perfect rapture? Then rejoice! Truly you are blessed!"

— Geon of the Emperor's Children

A pair of Kakophoni bearing Sonic Shriekers.

The Kakophoni (meaning "Cachophony" when translated into Low Gothic) were a specialised anomalous support unit of the Emperor's Children Legion, created during the closing days of the Great Crusade by Chief Apothecary Fabius who sought to "perfect" the gene-seed of the Astartes by unlocking the secrets of the Emperor's original genetic engineering and then "improving" upon it through the use of forbidden Chaos knowledge.

Enhanced with these forbidden surgical augments and formidable psycho-sonic weaponry, which was based in part on xenos designs pioneered by the serpentine Laer, the Kakophoni were unleashed against the Loyalist forces of the Imperium during the Istvaan III Atrocity and the Drop Site Massacre on Istvaan V.


Kakophony Sketch

Ancient Remembrancer sketch depicting Kakophoni based upon various pict-caputures in the Segmentum Obscurus war zone; these Astares possessed variant Power Armour of an unknown designation and modification; there was also extensive modification to helm apparatus auditory receiver/broadcast/address functions and amplification.

The birth of the Kakophoni goes back to the dawn of the Horus Heresy. Of the twenty original Space Marine Legions founded by the Emperor Himself, the Emperor's Children were Legion III. They were the only Legion permitted to use the Emperor's name and to wear His own symbol -- the Palatine Aquila. Their leader -- the Primarch Fulgrim -- sought perfection in all his actions and led them on their quest to become the living embodiment of everything the Legiones Astartes should be.

They were noble, fierce in battle, yet civilised, and above all fanatically loyal to the Emperor. Beneath Fulgrim's meticulous eye, his Legion sought to honour the Emperor; with perfection as the ultimate goal, they obeyed battlefield doctrine to the letter, while tactics and strategy were studied in minute detail and the Emperor's words and decrees were memorised and adhered to in every way. Their reverence and adoration for the Emperor bordered on the fanatical. From this pinnacle, they fell far further than their brothers.

The quest for perfection consumed the Emperor's Children in body as well as spirit. For some it was not enough to achieve the accolade of perfection, they thirsted to embody that perfection. For these warriors it was not enough that the Emperor had crafted their flesh, and shaped each with insight and knowledge no other could rival; their granted state was simply the beginning of an unfinished path.

Evidence would emerge during the Heresy that many years before Horus' treachery was made manifest, a few amongst the Emperor's Children, most notably their Chief Apothecary Fabius, believed that they could perhaps improve on what gene-seed, human breeding and the Emperor's design had made them.

They tampered with implanted gene-seed organs, analysed and modified Progenoids, and undertook surgical augmentation of those willing subjects who shared their obsessions. The blasphemies of flesh this belief would birth only emerged in the darkest years of the great interstellar civil war, but its roots must have grown long before the Emperor's Children trod the hot ashes of Istvaan III.

Sonic Shrieker

Ancient sketch depicting anomalous Sonic Weapon; design unknown, Forge World/fabricate of construction unknown.

Soon after the treachery of the Istvaan III Atrocity, a terrible force took hold of the Emperor's Children Legion under their master Fulgrim, and for many the fall was swift and terrible to behold. Practices and experiments long secret and carried out with dire caution were unleashed and fused with malign forces from beyond the boundaries of reality.

One of the first malignant tools made manifest were the strange and experimental psycho-sonic weapons that would come to be known as the Cacophony or Kakophoni in High Gothic. These weapons proved savagely powerful but also dangerously unpredictable in their first incarnation.

Marius Vairosean

Captain Marius Vairosean, in the thralls of the Maraviglia, picks up one of the strange sonic instruments created by Bequa Kynska.

This sonic weaponry is descended from the musical instruments invented by the famed composer Bequa Kynska of Terra, who accompanied the Emperor's Children's 28th Expeditionary Fleet as a Remembrancer aboard the Battle Barge Pride of the Emperor during the last days of the Great Crusade. Kynska was a jaded musician always in search of further sensations to create more exhilarating and all-encompassing music, which made her an easy target for Slaaneshi corruption.

After Kynska accompanied many of the 28th Expedition's Remembrancers to the temple dedicated to Slaanesh on the Xenos World of Laeran, she was touched by the Chaos corruption of that foul place and slowly sought to create the ultimate orchestral piece that she believed could capture the wondrous sounds she had heard within the Laer temple.

Her ultimate masterpiece was a symphony she named the Maraviglia and which she performed for Fulgrim and all the assembled Astartes of the Emperor's Children and their support personnel within the Remebrancers' lounge called La Fenice aboard the Pride of the Emperor. To recreate the sounds she had heard, Kynska created new musical instruments whose sonic powers could also be used for destruction when employed by an individual already corrupted by Slaanesh.

As the Maraviglia began, the cachophony of sound unleashed by these instruments acted as a ritual that opened a link between realspace and the Warp and allowed the power of Slaanesh to directly touch the audience. During the "performance" it was noted that the musical instruments were able to produce effects variously disorienting, stimulating and downright murderous.

Chaos mutations ran rampant through the audience and Astartes and mortal humans alike were so overwhelmed by sensation and uncontrollable emotions that they unleashed an orgy of both sensual hedonism and the most base forms of murder upon one another. Ultimately, the music summoned five Lesser Daemons of Slaanesh known as Daemonettes from the Warp who possessed the bodies of Kynska and several of her singers and joined in the slaughter.

During this part of the concert, several Emperor's Children Astartes left their seats and took up the instruments to try and keep the daemonic music playing and in the course of their untrained fumblings with the instruments discovered that they could unleash waves of destructive sonic power filled with the psychic strength of Chaos.

Commanded by the Legion's Third Captain Marius Vairosean, on Istvaan V the first of these weapons were unleashed by members of the Emperor's Children who had already begun to degenerate and mutilate themselves in response to the canker of Warp-taint to which they had been exposed, a progression of gathering madness and physical corruption that would accelerate at a frightening rate thanks to continued exposure to the reality-rending effects of their perverted weaponry. These Chaos-corrupted Astartes became the first Noise Marines.

Unit Composition

  • 4-9 Chora (Squad Members)
  • 1 Orchestrator (Squad Leader)


  • Power Armour
  • The Cacophony - The Kakophoni manifest a variety of experimental and unique psycho-sonic weapons, made from an irrational fusion of Imperial and alien technology wedded with the whispered secrets of nightmare intelligence from beyond. These unstable devices are able to unleash blasts of screaming, discordant energy that can rupture flesh and incinerate metal. Their most terrifying ability, however, is to open up the minds of those they touch to the manifold and fatal horrors of the Warp.
  • Sonic Shrieker - Towards the end of the Great Crusade, the IIIrd Legion's armourers and Apothecaries had begun to experiment with surgical augments and psycho-sonic weaponry based in part on xenos designs. Although their true breakthroughs in these fields would not occur until given unholy impetus as inspiration during the Legion's fall, some success had already been reached in creating effective combat implants which were finding selective use as the Horus Heresy dawned.
  • Bolt Pistol
  • Combat Knife or Chainsword (Orchestrator Only)
  • Frag Grenades
  • Krak Grenades

Optional Wargear


  • The Horus Heresy - Book One: Betrayal (Forge World Series) by Alan Bligh, pg. 108
  • The Horus Heresy - Book Two: Massacre (Forge World Series) by Alan Bligh, pp. 218, 222-223
  • Fulgrim (Novel) by Graham McNeill
  • Angel Exterminatus (Novel) by Graham McNeill
  • Warhammer 40,000: Index Chaotica - Noise Marines (Digital Edition)
  • Forge World - Emperor's Children Legion Kakophoni


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