The Broken are Daemons that have had their nature changed due to an attempted possesion of a Derkallen. The process is painful for the Daemon, and they end up irreparably changed. No longer connected to their gods and lacking purpose, the Broken live an empty existence. They can be summoned by Psykers, though it is Derkallen Magisters that usually summon them. Many Broken have joined the Daemonic legion of Asumael the Hollow Lord, who is currently the most powerful of their kind.
To Daemons the Derkallen represent a highly unusual and unsettling existence. The Derkallen do not have proper souls. As such they should be immune to Chaos for the most part, and unable to be percieved by Daemons within the Warp. This is not the case however. The Derkallen possess the Palash, a false soul that serves a number of functions including allowing them to behave as if they had emotions and use Psychic powers. The Palash is a physical part of the Derkallen, but it is also a surrogate soul. This means that it can be percieved within the Psychic realms of the Warp.
Daemons view the Palash as the souls of a Psyker, given that the Palash gives every derkallen some level of Psychic power. However while they would usually attack such a soul with gusto, Daemons hesitate when they encounter a Palash in the Warp. The Palash gives off an aura that Daemons find strange and disturbing. This aura is a direct result of the fact that the Palash is not an actual soul. The feeling a Daemon gets when around a Palash is usually enough to deter it from attepting a possession, but some Daemons attempt to do so regardless of their instincts.
These Daemons voraciously attack the Palash of the Derkallen. These rare Daemons inevitably succeed in their attempts at possession. The aura that protects the Derkallen makes possession rare, so Derkallen rarely recieve any training to resist Daemonic attack if ever.
The Daemon enters the Derkallen, taking control. However once it has possessed the Derkallen the daemon becomes trapped in the Derkallen's Palash until the death of its host. The inside of the Palash is an environment that is unnatural to a Daemon. Having only twisted facsimiles of proper emotion and unnatural Psychic energy, the Palash becomes a torture chamber for the Daemon. The Daemon still has full control over the Derkallen during this time, but it is under so much anguish that it rarely does anything besides writhe in pain.
Eventually the Derkallen dies under the strain of the Daemonic possession. As it dies the Palash releases its hold on its captive. The Daemon emerges irreversibly changed. Its time within the Palash warped its nature, and severed its connection with its god. A Broken has been born.
The Broken have changed considerably from their previous natures. All Broken embody pointlessness and nihilism. To some extent their behaviors will mirror this. Some Daemons will have powers, and act in a way that mirrored their former selves. However their actions will be merely a pointless act that they perpetrate on some vestige of their former instincts. Others will in fact contradict their previous nature, seeking to undo whatever they previously supported.
All Broken are emotionless, and without any passion of any kind. These beings envy those with passion and purpose, the very things that they lost. To some extent or another all Broken lament their current ordeal. As a result while most Broken simply follow their futile nature blindly, there are some that act in order to steal the purpose from those that possess it, or to destroy those that possess what they do not have out of spite.
Broken can be summoned by mortal creatures.
The majority of the Broken are former Lesser Daemons. This is because the superior servants of the Gods such as Daemon Princes and Greater Daemons can not be bothered with such trivialities like possessing some unusual soul within the Warp. Furthermore many already know of the effects of the Palash on Daemons, and simply ignore them when encountered. Though there are still some that try in rare cases, and they often become unique, powerful Broken.
Grey Slayers are Bloodletters that have become Broken. They resemble their former form quite closely. Their bodies maintain their wirey, yet strong physique. They still have the great crests and horns of their former form. However there are two major differences. The first of which being that their blood red hide has lost all color, and turned grey. The second difference in form is that they have lost all facial features save their eyes, a trait they have in common with the Derkallen that broke them. Where once they would give blood-curdling roars, now the Daemons are silent. They continue with their former occupation, slaughtering at random, but now it is merely an empty act done on instinct. They no longer feel the rage and passion of battle. They only kill due to a dead memory of what they once were.
Formerly the voluptuous Daemonettes of Slaanesh, the Passionless are now twisted mockeries of what they once were. They feel nothing, niether physical or emotional. They are numb all the way through. They still keep the beautiful, feminine forms of their former life, though they do not possess the crab claws, or other exotic mutations of normal Daemonettes. Their skin is now pale, and they wear veils upon their faces at all times. The power of the Passionless is a particularly frightening one, especially for followers of Slaanesh. The Passionless envy those who can feel sensation in their own way, and they have the power to remove the ability to feel from others. They can strip their victims of one or more of their emotions, or can permenently remove one or more of the physical senses. In the worse case a victim of a Passionless could end up stripped of every sensation, unable to percieve any stimulus from the outside world, and unable to feel any emotion what so ever. It is little wonder that these Daemons are perhaps one of the few things that followers of Slaanesh truly hate and fear.
Former Plaguebearers. The rotting flesh of these creatures has hardened, and turned into stone. As a result of the supernatural stone that composes the creature's body they are very resiliant against damage. Their horned head is gone. In its stead is merely the creature's great cyclopian eye. The Undoers have the unique ability to turn any object they touch into dust, a symbol of the impermanence of all things. However this is not the slow wasting ruin promised by Nurgle, and as such does little to please him.
Hopekillers useed to be the Horrors of Tzeentch. The once animated creatures are now silent. As a part of their transformation the bodies of the Hopekillers have crystalized into one shape made of ice instead of the constantly shifting flesh that they once possessed. Where once the chattering creatures would hurl bolts of Warp Fire and blasts of arcane energy, they now use a very different weapon, and one for that matter that is an affront to their former master. The Hopekillers can fire blasts of Stasis Frost, a substance that will permanently and irreversibly freeze any that come in contact with it. This insures that whoever, or whatever has been frozen will never change in any way.