Hollow Knight Vessel Theory
This theory comes from the assumption that every single vessel has a shade/practically infinite lives.
This one guiding principle is WAY harder to work around than you'd think at first (even though it might be generally accepted as canon?)...but I think I finally put it together
STEEL SOUL IS NOT TREATED AS CANON (The Knight has a Shade)
Forms of the Knight's shade appear in most endings, most importantly the Dream No More ending.
In Silksong, Hornet's cocoon does not have its own entry anywhere, and really isn't lore important, so Steel Soul Hornet could be canon. This is directly contrasted by Hollow Knight, where the shade has its own journal entry and several NPCs remark on it ominously (ex. confessor JiJi).
The siblings found in the abyss strongly resemble the Knight's own shade, except more ragged and tattered.
Similarities in the Hunter's Journal entry for Shade and Sibling
Fragment of a lingering will vs. echo of a previous life, an imprint of something left after death
Would make thematic sense in making the Knight less "special", since all vessels have shades.
PART 2: OBVIOUS WRENCHES IN THE WORKS
What the HELL is going on with nosk's vessel victims? ✅
What the HELL is going on with the Greenpath Vessel (Geep)? ✅
Why weren't there any vessels still alive, wandering around in the Abyss when we got there? ✅
Why were there only vessels in certain places in the Abyss, and why were they laid out so haphazardly on the random platforms they fell on during the climb❓
I have formulated explanations for all of the wrenches notated with a "✅"!
I don't think there will ever be a truly satisfying answer to the last one, just by the nature of video games sometimes sacrificing cohesion for powerful emotional moments...
PART 3: HOW CAN THE WRENCHES BE EXPLAINED:
-Why are there just CORPSES lying around if each vessel had infinite attempts?-
Explains Geep, Nosk vessels
1.a.) BENCH THEORY+THE KNIGHT INTERLUDE
First of all, just don't think about the metaphysics of having possibly more than one corpse and one shade lying around, as will be implied later. It doesn't make sense in game, it's not going to start making sense now.
Benches in Hollow Knight serve as spawnpoints for the player character. You die, you wake up on your last bench. But why?
What if benches are places that the Knight internally categorizes as "safe"? What if vessels only respawn in places they consider safe?
The Knight is lonely by nature, and if you buy into the headcanon I'm selling (0$, it's on sale), they never quite felt "at home" in the Abyss surrounded by their siblings. Or anywhere else throughout the game, which is why they can freely set their spawnpoint in strange locations they have no personal connection to. THIS is what differentiated them from all their siblings: no special ability, no stricter adherence to the Pale King's ill-defined hollowness doctrine – just a well of loneliness and inability to find comfort so deep that they'll gladly consider that fuckass Beast's Den bench "safe enough".
There are no safe places in the Abyss.
1.b.) ABYSS SPAWNPOINT & HOW VESSELS DIE
Since there is nowhere even close to welcoming and safe in the nightmare that is the Abyss, I theorize that the Vessels respawn in their eggs. Some are on the surface, but many more are likely hidden under the corpse pile.
To nip a wrench in the bud, I'm going to assume the birthplace tunnels aren't actually real in the way they're shown in game. The dreamlike quality of the birthplace+birthplace cutscene, and ESPECIALLY the fact that it is
1. Inaccessible afterwards
2. Not drawn on the map (as opposed to other single-use locations like the Cast-Off Shell)
lead me to believe the tunnels themselves don't actually exist normally.
So, when a Sibling tries to respawn, most of them will instantly find that they are buried under literally countless inert shells, and get basically insta-killed by the pressure.
Perhaps in the beginning (for example, during the birthplace cutscene, where the Baby Pit is noticeably smaller) vessels could feasibly climb their way out of their eggs to the Abyss proper, as seen with the Knight. But, by the time all of the vessels had been born, it is likely that the sheer force of all the vessels above them would just immediately kill anything below.
So, how do vessels die? First of all, there was no readily accessible soul in the Abyss for at least a while, as there are no shadow creepers in the birthplace cutscene. Do siblings give soul? Probably (Pure Vessel does), although that opens up the worrying and disappointingly untapped world of serial killer Vessels and insanely high-stakes babyfights (it's basically like I read the plan for the void expansion stretch goal, I know. Sometimes my genius, it frightens me...)
ANYWAY, no soul=no focusing=every mask down is a mask down FOREVER
There are spikes in the Abyss, violent Abyss tendrils, and (almost certainly) fall damage. (Headcanon that vessels only take fall damage when they land on their mask from this fic)
It makes sense that staying alive for centuries under these conditions, along with the hopelessness of their situation, pushed so many vessels to give up and stop even trying to respawn.
The Nosk vessels escaped into Deepnest (somehow) directly from the Abyss, did not find a bench/safe place, and when they were killed by Nosk they respawned in the Vessel Compressor
Then, there is the theory-destroying case of Geep, the beloved mothwing cloak vessel. This one will rely on FAR MORE unsupported assumptions than the locationally convenient Nosk vessels.
I thought of three reasons Geep would die frfr (as shown) within this shade premise:
Supported by: the dreamer encounter the Knight experiences in the same arena. The current-day dreamers were strong enough to send the Knight to the dream realm when they came to their (likely most influential) spot of worship, so it's not impossible that they would've been strong enough in the past to do the same thing all the way in Greenpath.
THE WRENCH: Hornet is heavily implied to have killed Geep directly. It also seems quite out-of-character for her to stab someone she didn't beat in a fair fight (assuming the dreamer interaction happens after the vessel beats Hornet, as in the Knight's experience).
This also gets a little messy when considering that the Seer apparently didn't help them, and did not so much as hint that there might've been another vessel in the Dream Realm.
2. They gave up for some reason
Supported by: the 8.6% of players that never made it past Hornet 1. Highly unlikely but convenient and easy to assume when first contemplating why the hell Geep is dead when we aren't.
THE WRENCH: cmon man you really think a vessel that goes through the trouble of ESCAPING THE ABYSS (we don't even know how to do that like damn) would just ragequit life like that. be fr. shaw.
My bench theory actually came about SPECIFICALLY to explain this ONE character. Now, logically, it is safe to assume that Geep DID bench sometime during their journey through Hallownest from the Abyss all the way up to Greenpath. This is where the emotional aspect comes in.
THE WRENCH: This theory assumes a lot about a character we know essentially NOTHING about. Anyway...
Geep wasn't meant to be alone. They loved their siblings and couldn't bring themselves to fully disconnect from their time in the Abyss, at least consciously. They were separated from the siblings they probably escaped alongside, and struggled all the way to Greenpath on their own (likely picking up mothwing cloak on the way). When they fought Hornet for the first time and died, like all of us probably did, they respawned in the Abyss. In their egg.
All because they couldn't let go of their past, because they couldn't stand being alone.
The Greenpath Vessel respawned in the Abyss because of emotional attachment to their past/friends
Explains Lost Kin, aspects of The Hollow Knight
Degenerative illness is an interesting concept when considering things that respawn upon death–especially when the illness doesn't necessarily kill. Based on vibes, it can be inferred that Vessels don't really get sick (because of their undead status, godly heritage, void-ness, etc...) EXCEPT with the Radiance's Infection. Since the Infection targets the mind and not the body, "impure" vessels with emotions are susceptible to it. Assuming the Infection doesn't kill them directly, which is textually supported by:
1.) Myla's scream upon dying, implying that she never truly DIED while infected, instead losing complete control of her mind and actions.
2.) Broken Vessel's heartbreaking little reach for help upon dying. They were probably alive in there the whole time, even with a completely destroyed shell, and the Infection was the only thing keeping them together. Once it was excised, so were they.
it's safe to assume infected vessels are cursed to deal with it forever. It leaves them in stasis.
For Broken Vessel specifically, I think they were infected the whole time, even as the husk we see when we enter their arena. Hornet was probably the one to "kill" them, maybe because they were infected, and that left them in a mindless basically-coma until we show up and the Radiance remembers she can use that puppet.
The Infection may have a strange effect on Vessels and Vessel lifecycles. Unfortunately, our sample size is 1.5, so we don't really know what happens to infected vessels when they're released from the Infection, but it seems like their fate depends on how much damage their shell had sustained at the time they were released. The Hollow Knight shakes it off like a chad in the Embrace the Void+flower endings. Broken Vessel...dies? Like, for real? I'm not counting this as a COMPLETE strike against the theory, but it might just be the most damning one.
My explanations for Broken Vessel seemingly just dying with no shade in sight are:
1.) Broken Vessel DID respawn somewhere, we just don't know the deets
Ngl, this one's paper-thin. It would make us feel better at least? This includes the possibility of them respawning in the Abyss, although I find it unlikely they never died before we killed them, given that they lived in Hallownest proper long enough to grow taller.
THE WRENCH: You can fight their ghost. That's not really "moved on and is still alive and kicking somewhere else" behavior.
2.) Long-term proximity to Infection can change void's properties/destroy void
Being infected and so close for death for so long may have warped BV's relationship with their shade/void. So much time spent with the Light in them may have burned out most of their void and made them unable to properly respawn, so when the Knight killed them, they died forever, leaving behind the dream-ghost of their shell, but no shade.
THE WRENCH: The Hollow Knight does not seem to work this way. In the Dream No More ending, a form of their shade is clearly shown assisting the Knight in the Radiance's destruction.
UNWRENCH?: There is no guarantee that the Hollow Knight would react the same as an average Joe Vessel to the Infection, or that the Dream No More ending is analogous to BV's situation since it all happened in the Dream Realm.
For one, THK was exposed to a LOT more of the infection than BV, which may have changed the effects. They were also specifically trained to hold the Infection, which probably didn't work at all but MIGHT have let them hold onto their shade better. Finally, it is possible there were some protections placed on THK to alter the way their shade functioned: some theorize that it held their shade to their shell so they couldn't escape, but it could've simply protected the shade from being destroyed by the fury of the Radiance.
It's pretty clear that I'm more on board with explanation 2. Let's just pretend it's a solid
Broken Vessel/Lost Kin was held in stasis and had their Shade altered by the Infection, and when they were released, they just died as a normal bug would
Explains why there aren't Vessels still alive in the Abyss
Why are all the Vessels dead by the time we get to the Abyss? Statistically, (and screenshotily) at least a few of those eggs were high enough for some of the siblings to be able to respawn without being crushed to death.
Well, what do you do with an eternity of suffering?
...this one gets depressing, folks.
I think it makes the most sense to assume that it took eons to discover a pathway out of the Abyss. That way, only the most determined, strong-willed vessels would have made it to the outside world. And everyone else, including those who could respawn without consequence, were faced with a dilemma. What's even the point of living in hell if you could just...not do that?
Eventually, the Vessels either died and got sent to the torment backrooms, or died and decided there was nothing worth coming back for. Either way, they ended up the same: floating around as just their shades, passively observing the world but not interacting with it in any meaningful way.
I believe the Knight's shade is only antagonistic towards it because of the Knight's personal deeply held complexes. Read my fic if you want to hear more about that, but the main idea is that the Sibling's shades used to be chill and non-aggressive, and possibly held the memories/personalities of their whole selves.
3.b.) WHAT HAPPENED TO THE SIBLINGS?
As time marched on, the Siblings that had abandoned their shells grew more and more disconnected from themselves. Without a soul-forged housing (shell) to anchor them, they began to lose their sense of self and started to become just another piece of the Void. Eventually, they become the Siblings we recognize from the game: tattered, dangerous to their own kin, and lifeless.
By the time the surviving Vessels found a way out, it was probably too late to save the Siblings from their own listless meanderings. The worst part is, every Sibling COULD'VE BEEN brought back. All of the Abyss's vessels have the capacity to be revived. But due to their siblings' inability to communicate that they found an exit, the Void's hivemind overtaking them, or sheer bad luck, it's just too late for them.
The best they can get is being allowed to rest in peace at the end of the Dream No More ending.
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I actually have NO idea if this is just widely-held fanon that no one talks about, or if it's a crack theory that most would disagree with. I personally have not seen any Vessel theories specifically going through and deconstructing the inconsistencies in the likely fact that all Vessels have shades, so I thought I'd throw my own theories in the ring!
Please let me know ways you may disagree with these theories, and what contractions I missed! I found some just as I was typing this up, so I'm sure they are more. Will add more screenshots for readability eventually probably.