u/thelucas2000

Quick rundown

Lifeblood, formally known as Plasmium, is a substance in the Hollow Knight universe that provides with biological organisms with enhancements. Able to provide health benefits and even shown to be able to resuscitate bugs in Silksong.

In Hollow Knight, all we know about Plasmium is that it just gives us more health and that there is multiple deposits that grow (like plants) with "lifeseeds" within.

We also know that there is a dream Plasmium being, possibly a higher being, but this being won't be the focus of this post. We do learn from Salubra that Plasmium is "taboo", and we also learn from Joni that bugs who partake in Plasmium are considered heretical, except it was never really explained why.

The change in Silksong

In Silksong, we learn two things about Plasmium:

• Plasmium is a plague of body in a way, able to transmutate bugs in ways similar to the infection
• Plasmium and Void are completely neutral to each other, void being unable to take influence over Plasmified enemies in the Wormways (also there being no void tendrils there), and Plasmium not being able to transmutate void entities (as shown by The Knight's inability to overdose compared to Hornet)

In addition, Plasmium itself cannot be read in mind like normal bugs and even some higher beings. Plasmified bugs can be affected by the needolin, but Plasmium beings like the lifeseeds cannot be affected by the needolin nor dream nail. So there is a clear distinction:

• Pure Plasmium is seemingly immune to any form of mind reading/alteration
• Plasmified beings (beings who were not originally plasmium) can however be altered, but to a limited degree (Plasmified bugs in the Wormways do not sing their thoughts out loud, they just sing along like the Bellbeast).

So, this puts into perspective that Plasmium is a form of higher substance akin to SOUL, DREAM, and VOID. But we just don't fully know the extents which makes Plasmium itself important, just that it is comparable.

Now... How did Plasmium become outlawed in Hallownest?

The story of Plasmium in Hallownest

The story begins in Deepnest. For starters, I don't believe this is a retcon but more-so an instance of TC leaving clues and refusing to elaborate (until Silksong). Hornet does drop the first clue of how the story begins in the journal entry for the Plasmidas:

"In my home caves, where once this substance was allowed to flourish, I saw similar aberrations". There are three important key details in this entry:

• Hornet states that Plasmium was once allowed to grow and flourish on Deepnest. We can conclude this because she specifically says "home caves"; Hornet was birthed in Deepnest and grew there before moving to The Hive to train with Vespa
• Plasmium was allowed to flourish at least once. The usage of the words "was once allowed" means contextually that Plasmium has at some point become outlawed to grow, explaining the title of "Heretic" to Joni and the adjective of "taboo" from Salubra
• Similarly to Wormways, Plasmium caused similar aberrations in Deepnest. Possibly meaning that there once was an outbreak of Plasmium in Deepnest

Finally, it is worth noting that all remaining deposits of Plasmium in Hallownest are all hidden, not easily found. Now... Here is the important question... Where is the evidence of a "Plasmified Deepnest"? We don't really see anything like this. Why isn't Galien's Corpse walking around Deepnest? Why aren't there Plasmified Weavers?

My answer to this question is a theory that admittedly lacks more evidence but is at least backed up by common biology; Fungi.

Deepnest is home to a strange sort of fungi seemingly different from the kind found in Fungal Wastes, a type of fungi that is bioluminescent and that seemingly leaks soul particles as the player walks amongst its foliage. Noticeably, the growths of this fungi is significantly larger in one single spot in Deepnest; Galien's arena. Galien's arena just also happens to be the same room housing the largest deposit of Plasmium in Deepnest... Also housing the largest growths of glowing mushrooms. Following basic fungi biology, fungus is very resilient, able to grow out of nearly anything and specifically able to grow out of dead biological matter (something Plasmium also uses to spread (but isn't limited to)).

This in mind, assuming that the Weavers/bugs of Hallownest planted these mushrooms throughout the Deepnest to halt the growth of Plasmium, the fungus becoming a common part of its ecosystem as it maintains Plasmium in check.

Timeline

TLDR, Here is what happens with Plasmium in Hallownest:

• Plasmium appears in Hallownest/Deepnest
• Plasmium is allowed to flourish in Deepnest
• Deepnest becomes seemingly partly Plasmified at some point
• Because Hallownest isn't abandoned like Pharloom, there are bugs to stop the growth, and they plant a type of fungus to leech off the Plasmium growth
• The Plasmium infection is controlled
• Plasmium becomes outlawed, becoming a taboo and anyone who partakes in it (like Joni) being classified as a heretic
• Hornet observes the exact scenario which would've happened in Deepnest in the Wormways, except now in Pharloom there is no one alive or who cares enough to stop it (in addition to the Wormways being abandoned), and the one person who cares about Plasmium is instead carelessly injecting it into the natural habitat.

Nosk is a boss found in the hidden corners of Deepnest, showing itself once outside of its hidden lair to lure players/give a mental note that there is something within the region that looks like the player.

Eventually, players will run into Nosk; a creepy, slender creature with a glowing bulb sac of infection. Waiting in a lair with multiple vessels and other creatures (presumably past prey) hanging from the ceiling, in addition to a wake of corpses left behind on the path.

But... What exactly IS Nosk? Is it a bug? Is it a monster...? A new type of organism...?

Well, Hornet best describes what Nosk could be when speaking in regards of the Shadow Charger: "They seem such simple bugs... but I suspect they are not truly our cousins."

The true nature of Nosk: One of The Abyss's many monstrosities.

Nosk, in my observation, is simply just another creature that originates from the abyss. Whether it is a unique creature or just part of a group of species is unknown, but there is in my opinion enough observable evidence to be able to confidently assume Nosk is just part of this environment.

To begin with — The proximity between The Abyss and Deepnest. Nosk's lair is the second deepest and closest region to the basin/abyss layer in Hollow Knight. This is evident by the fact that there are multiple vessels bodies located in Nosk's lair. Evidently, this lair is a (popular) exit from the Abyss. Nosk being a creature of higher intelligence (or instinct?) simply took camp here and swiped off any vessels escaping through is what one can conclude.

Putting aside the obvious geographical connection, this being that The Abyss is next door from Deepnest and Nosk's lair, you also have the visual cues that this is another creature likely originating from this underworld.

• Nosk's "silk" is black. No other silk in either Silksong or Hollow Knight have a black appearance; the only instance we see blackened silk is in Pharloom when the void calamity occurs.
• Nosk's body assumes a hostile and dangerous form. I choose the word "assumes" carefully because Nosk is a shape shifter. When Nosk takes off its disguise, this is the form it assumes. A form that is barbed with spikes on its back, slender and eerie extremities, and a cage around the infection heart. Similarly, Hornet has some things to say about the Void Tendrils, another form of "sentience" located within The Abyss, "In the barbed forms it chooses its nature can be seen clear.". Both Nosk and Void Tendrils choose a form that is barbed and hostile, both share a similar nature.
• Nosk has no dream nail dialogue. Additionally, no other "bug" originating from The Abyss has any dream nail dialogue. It is unknown exactly what causes this and how Nosk exactly "thinks" to ambush its prey and have the intelligence it does to do the things it does (or if it's by instinct), but Nosk, like all other Abyss bugs, has no discernible mind to read.

Conclusion

I think this long enigma within the community has come to an end. Is Nosk void? No. Is Nosk however a creature from The Abyss? In my opinion, there is ample evidence that this is the case. There is no other instance of a creature like this existing in Hallownest. If anything, there are instead instances of creatures with similar features and nature from the abyss than anywhere else.

There is also something interesting the Hunter's Journal notes: "In the deepest darkness, there are beasts who wear faces stolen from your memories and pluck at the strings in your heart. Know yourself, and stay strong." Note the terms "deepest darkness". In this case, a being coming from the deepest darkness in a world that does, quite literally, have the deepest darkness (known as The Abyss) to me quite literally reads that Nosk is a creature found within this place. It's not even just the speculative aspect of this, but it is known that void has the ability to psychologically manipulate and alter other bugs. We see evidence of this in the Hallownest's Abyss Lighthouse, where the lighthouse keeper is manipulated, or better worded, "called by the sea" into turning off the lighthouse.

Finally, the Hall of Gods refers to Nosk as "Everchanging god of the faceless". While this could be q literal description of Nosk, The Abyss does have a reputation of housing other faceless sentient forms (gloom bugs, tendrils), Nosk wouldn't stand out here either.