Though the dreamer sleeps, it seems to maintain a rudimentary awareness of its slumber; whenever it resists the lullaby beguiling it, fissures and hemorrhages form across the multiverse. These wounds tear apart the seams while a blackened film emerges from the ruptured sections. This blood, oily in texture and shade, contaminates the region.

At first, the effects can be challenging to discern with the mortal eye, and by the time one can observe the first pool, it already has planted its seeds. This dross is sentient, birthing creations known as the outsiders charged with broadcasting its necrosis. This otherworldly serum often is accompanied by a haunting dirge or a ghastly fog—such a blight serving a natural function within the cosmos.

​The pathogen has already consumed many levels of reality; twisted effigies from each added to the possible manifestations it might wear. This adaptive and resilient organism possesses an alien language, often depicted as crashing waves against the rocks. The forms they generate can be humanoid, animalistic, amorphous, or even inanimate - but no matter their design, that signature blackened fluid coats their forms, joined with cancerous growths and writhing barbed tendrils. Carapaces shield the most elite of their collective, the hues of which often shift with each step and lack the revolting additions to their bodies typical of The Defiled. Favoring areas of seclusion and setting their gaze upon the vulnerable regions, unknowingly prime for subsumption, the Defilement brazenly flaunts their sentience. The stages of infection fit under four categories, and as the disease proliferates, so too does their ability to rationalize within a given space.​

​Paradoxically, whenever a universe isn't ripe for transcendence, The Defilement maintains the cradlesong incarcerating the dreamer. As time passes, they begin to trickle into the plane; initially, their interference may appear small, easy to miss, before rapidly swelling into a boisterous tempest. In actuality, the Defilement is not a disease; Rather it is a symptom. They exist because of the Dreamer and their principles permeate within it, yet it does not explicitly follow their will; it destroys and corrupts aspects of reality because doing so is in its nature. However, that motivation gradually moves towards its logical conclusion. The aforementioned small rifts manifest everywhere, either in long-forgotten or destruction-marred pockets.

If their fluid is ingested, or the feelers of those twisted creatures rip into the body of an organism, the victim will become marked, becoming an unknown patient. At first, no changes will be apparent, but in time, their minds will begin to rot, yielding to the whims and desires of the Outsiders. Magic, however, seems to serve as a natural, albeit temporary, barrier - once the reserves are depleted, nothing is left to halt the infection. The entire process can take from days to weeks. All things must end, and from its syrupy depths, new seeds of evolution are sown to start the age of nightmares.