The description for the Follower Torch notes the historical use of fire to combat a “pus” manifestation of the Abyss within man. Indeed, the Dark of humanity has produced a viscous substance akin to pus in past games, and flame has always been the means to drive away darkness. However, we have never before seen such pus burst out of Undead in the vague form of a serpent — complete with similar glowing-red eyes and tree-like bone protrusions forming a spine, claws, and teeth. At the same time, it isn’t that unexpected a shape to take. Manus exhibited similar symptoms after his humanity went wild in the original Dark Souls. Likewise, both the Dark and serpents have long been associated with greed and the Undead, and the Dark is closest in nature to the universe’s primal state. Add to it the link between snakes and failures at being dragons, and the pus’ somewhat draconic form is appropriate. Of course, all of this also implies Undead to be particularly susceptible to spawning this pus of man.
War torch that the revenants of Farron used. It has been made into a weapon along with being a light.
It is said that a certain kind of the Abyss fills the inside of man with pus. Fire has long been an effective means to answer it.
Undead clergy in the Way of White wear large clothed lids on their backs so as to prevent them from becoming “seedbeds” of the Dark. Statues at both the Undead Settlement and the Cathedral of the Deep similarly portray a man hunched over in fear and despair as something sprouts from his back, his figure shrouded in a cloth as if to hide and perhaps contain this deformity — only for it to bulge against the draping. Variants of this statue remove the drape to reveal the budding growth enveloping the naked man, all with the same texture as the pus of man. This clear progression in the Dark consuming the body can thus only be a reference to the black ooze which burst out from a human’s heart area, mainly around the back. The Way of White’s concern about Undead in particular further suggests that it can be considered an extension of the Darksign.
Tunic that a clergyman who became Undead once wore. Unmistakable vibrant blue cloth.
It is said that the travelers in blue have been entrusted with a mission, and that those Undead carry large lids on their backs so as to not become seedbeds of Dark.
Adding credence to this notion, certain pus of man can belch up masses of their own matter, petrifying any who come in contact with the spew. The Dark is already associated with curses, but to inflict petrification in particular implies a specific cause. The densest Dark churning at the center of the pus must be sucking up the souls from the body with their touch. Without the power of Disparity, the flesh reverts to primordial matter, thereby turning the whole body to stone. In other words, it “eats” our life force the same as how humanity captured in the Darksign devours an Undead’s life force. And just as how Hollows’ souls have been consumed by their humanity, so too do their bodies sometimes become consumed by the pus that dark souls produce, hence both tend to mindlessly meander and thrash about.
While the pus of man’s intelligence may be wanting, its ties to the Dark are no less apparent than in its actual senses. According to the description of the Grand Archive Key, the library shuts its doors when the First Flame began to go dark in the Kiln and the pus of man began to run rampant within Lothric Castle, implying relative simultaneity between the two events. Considering that the Darksign appeared when the fire first began to wane, it makes sense for the pus to see a similar uptick with the Age of Dark drawing ever closer. The universe is shifting, and the Dark within man strains against its shackles in accordance with this cosmological change in alignment, instinctively anticipating the new era — all the more, with how long it has been delayed. In fact, the very concept of built-up debris fits well in this era of exacerbating stagnation.
The Consumed King’s isolated garden is still overrun with the pus by the time we arrive to the scene, a peculiar toxic swamp dotting the landscape. Unlike the one in Farron Keep, this bog is incredibly shallow yet undeniably there, though what lies beneath the layer of fluid looks like an almost frozen white, muddy material. Rotten slugs also inhabit this swamp, apparently swallowing dark gems as they loiter in the fluid. While their presence isn’t unimaginable for a forest garden, cut content reveals that these unassuming mollusks were originally supposed to be a dense “lump of Hollows” (亡者団子) in a slimy, gelatinous form, almost like pus. And with the Dark occasionally manifesting as a poison, we can be certain that this swamp stems from the pus of man roaming the area uninhibited. Furthermore, close inspection of the surrounding forest reveals the same plant life associated with stagnation springing up all around, and one of these pus snakes has dendrofied at the Lothric portion of the Dreg Heap.
In short, the pus is another symptom of the universe’s stagnation, much like the Dark’s dendrofication — explaining why we haven’t seen this particular variant of the Abyss in previous titles. Long has the consequence of fire’s light waited, slowly festering within man generation after generation. And as its power gains with fire’s wane, it all just bursts forth at once in a form so alien and yet so familiar. But if we are to imagine the stagnating Dark as symptoms of an infection, then it proves treatable. Nothing good comes from pus buildup; it must be drained out, one way or another. Like any Abyss, the pus of man fears the return of flame, perhaps especially so given its time spent in limbo. But no matter how we make it exit the body, this cleansing only targets the symptoms. The world’s disease continues to run its course, without a simple cure.