[OB] Secrets to Parshendi Forms, Thunderclasts, & Urithiru

[Wit Beyond Measure]

Parshendi Forms:

From Eshonai's prologue, after Gavilar explains the fabrial:

Quote

Captive like in a gemheart, she thought, attuning Awe. They’ve built devices that mimic how we apply the forms?

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 23). Tom Doherty Associates. Kindle Edition. 

 

When Venli first meets Timbre, at Eshonai's body:

Quote

Touching the bodies of the fallen was taboo. The old songs spoke of days when humans had hacked apart listener corpses, searching for gemhearts.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 339). Tom Doherty Associates. Kindle Edition. 

 

And then Venli bonds with Timbre:

Quote

Timbre pulsed from within her. Inside her gemheart.

“I’m still wearing one of their forms,” Venli said. “There was a Voidspren in my gemheart. How?”

Timbre pulsed to Resolve.

“You’ve done what? ...How can you keep a Voidspren captive?”

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1167). Tom Doherty Associates. Kindle Edition. 

 

And then when talking with the Fuzed named Rine:

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Humans don’t have gemhearts. How could they bond spren? It was unnatural. Yet somehow, their bond was more powerful than ours.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 834). Tom Doherty Associates. Kindle Edition. 

 

So the Nahel bond is more powerful than the Parshendi forms bond from capturing spren inside their gemhearts during highstorms to transform, presumably because the only stormlight needed for the Parshendi bond to work is during the bonding itself but not for any of the surges that come after the bond. 

When Aesudan and Amaram bonded with the Unmade spren, that seems to be a Parshendi bond since they swallowed gems (spheres) to make the bond, with Amaram's purple gemheart glowing in the end and Aesudan's gemheart glowing through her dress.

Thunderclasts

From the Thaylen City battle:

Quote

Venli got to watch the thunderclasts awaken.

Among the waiting spirits were two larger masses of energy—souls so warped, so mangled, they didn’t seem singer at all. One crawled into the stone ground, somehow inhabiting it like a spren taking residence in a gemheart. The stone became its form.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1090). Tom Doherty Associates. Kindle Edition. 

1

So the stone has gemhearts that, when inhabited by Voidspren, transform the stone into something else.  No wonder Szeth's people aren't stonewalkers, right?  Does stone have other forms?

Chasmfiends 

Chasmfiends obviously have gemhearts.  I think they must have other forms, too.  We know chasmfiends, skyeels, and greatshells all have the same spren. From the Kaza interlude, we know that greatshells do also have gemhearts.  Are these three different forms for the same being?  Do chasmfiends have other forms?   Are they also thunderclasts?

From Adolin's fight with the thunderclast:

Quote

A chasmfiend, he thought. It looks like a chasmfiend. The head, at least. The body was vaguely like a thick human skeleton.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1164). Tom Doherty Associates. Kindle Edition. 

2

Urithiru

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The tower of Urithiru was a skeleton, and these strata beneath Shallan’s fingers were veins that wrapped the bones, dividing and spreading across the entire body.  But what did those veins carry? Not blood. 

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 251). Tom Doherty Associates. Kindle Edition. 

 

And then:

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“The records below,” Navani said, “speak of this tower like a living thing. With a heart of emerald and ruby, and now these veins of garnet.”

...“If this tower was alive,” Dalinar said, “then it’s dead now.”

“Or sleeping. But if that’s the case, I have no idea how to wake it. We’ve tried infusing the heart like a fabrial, even had Renarin try to push Stormlight into it. Nothing’s worked.”

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1021). Tom Doherty Associates. Kindle Edition. 

 

So we wake it just as the Fuzed woke Thunderclasts from stone, right?  We bond Urithiru with a spren.  Or multiple spren.  Spren that can be trapped in a heart of emerald and ruby.

And from the gem library:

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Good night, dear Urithiru. Good night, sweet Sibling. Good night, Radiants. —From drawer 29-29, ruby

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 827). Tom Doherty Associates. Kindle Edition. 

 

Dude, is Urithiru the Sibling?!!!!  Sibling to the Nightwatcher and the Stormfather?

Quote

My research into the cognitive reflections of spren at the tower has been deeply illustrative. Some thought that the Sibling had withdrawn from men by intent—but I find counter to that theory. --From drawer 1-1, first zircon 

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 677). Tom Doherty Associates. Kindle Edition. 

So the Sibling was stolen away?

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Something is happening to the Sibling. I agree this is true, but the division among the Knights Radiant is not to blame. Our perceived worthiness is a separate issue.  --From drawer 1-1, third zircon

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 694). Tom Doherty Associates. Kindle Edition. 

And from the Stormfather's conversation with Dalinar:

Quote

"The Nightwatcher is like you. Are there others, though? Spren like you, or the Nightwatcher? Spren that are shadows of gods?”

There is … a third sibling. They are not with us.

“In hiding?”

No. Slumbering.

“Tell me more.”

No.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (pp. 1038-1039). Tom Doherty Associates. Kindle Edition. 

Slumbering!  Sleeping!  Just like Dalinar said Urithiru was!  And this is why the Radiant says goodnight to Urithiru, goodnight to the Sibling!

So we need to find the slumbering Sibling spren and restore her (or probably "them" because the Stormfather refers to the Sibling in the singular and the plural) to Urithiru's heart to waken Urithiru, right?  And what will a wakened Urithiru be like?  Will she move?  Will she protect?  Will she destroy?

***************************

Related ideas:

1. Fabrials are similar but not as alive as it would seem Urithiru will be and certainly not as alive as Parshendi, chasmfiends, or great shells.
2. Parshmen may not have had gemhearts until the first Everstorm, which restored their gemhearts and thus enabled them to now have forms, including Voidforms.
3. Different Parshendi forms likely come from different types of spren, with Voidform (forms of power) coming from corrupted or Unmade spren. 
4. Dullform might be having a gemheart with no spren bond since dullform is so close to parshmen.
5. Are there secrets to other cities, not just Urithiru?  Kabsal draws Kholinar as a triangular shape with three outlying wings and a peaked center (Pg 510 of WoK), which incidentally is the symbol on Gavilar's shardplate (Pg 29 of WoK), saying that the city was built on a rock formation already there.  The stone windblades of Kholinar seem particularly significant, where Kaladin says the interior corridor of the windblades reminds him of the strata at Urithiru (Pg 785 of OB).  I'm equally interested in the City of Shadows and even the City of Bells, but perhaps these cities are special in different ways.

 

Edited December 20, 2017 by Wit Beyond Measure

[Leuthie]

...and Braize is a giant gem that holds Odium and his minions with Heralds as keepers, much as Timbre is holding the voidsperen in Venli's gemheart.

[Draigon]

I don't have the text with me to look this up, but I think half-shards would be a special note in your theory. It's suggested that they are formed by trapping spren capable of a nahel bond rather than "mindless" spren.

[+Hoiditthroughthegrapevine]

3 hours ago, Wit Beyond Measure said:

Chasmfiends obviously have gemhearts.  I think they must have other forms, too.  We know chasmfiends, skyeels, and greatshells all have the same spren. From the Kaza interlude, we know that greatshells do also have gemhearts.  Are these three different forms for the same being?  Do chasmfiends have other forms?   Are they also thunderclasts?

This is very interesting @Wit Beyond Measure, also coupled with the fact that the fused say that the most powerful of their number have yet to return from damnation.

Here are a couple of relevant WoBs about Chasmfiends:

Quote

Questioner

Is there a relationship between the santhids and the chasmfiends?

Brandon Sanderson

Uhh… Yes.

Questioner

Besides them existing in the same place?

Brandon Sanderson

Oh, direct relationship? No, but in the family trees there is, y’know.

Quote

Questioner

What role will the chasmfiends play?

Brandon Sanderson

So there's a bunch of different roles for the chasmfiends that are all minor but-- For instance, I don't think anyone's made this connection, thunderclasts have chasmfiend-- it's part of the in-world inspiration for thunderclasts. And really chasmfiends exist in part to show off the symbiotic relationship between certain spren and certain creatures on Roshar. So when people who read the first book who know a little about physics can be like "Uhh, Mr. Sanderson" and I'm like "Well, look at these things that are flowing around this thing when it dies." It's an introduction of gemhearts and things like this. And the ability of certain creatures on Roshar to hold Investiture permanently, as Szeth says, rather than it seeping away like it does to humans.

So the great shells share a common ancestry, have evolved to hold investiture more permanently in their gemhearts, and the Chasmfiends have a known correspondence to Thunderclasts.

It is quite possible that great shells, with massive gemhearts, have held enough investiture to become cognitive shadows that can be respun out by the perpetual Odium desolation machine. If this is true, could those other more ancient and powerful souls waiting in Braize maybe be other greatshell spren/Cognitive Shadows capable of similarly creating Titan level monsters when bonding to one of the primary god substrates (Wind, Sea and Stone)?

Here's a tentative guess as to what this would look like:

• Cognitive shadow of fully pupated Chasmfiend ---> Thunderclast (titan of Earth and Stone)
• Cognitive shadow of Reshi Island ---> Cusicesh or some other Kraken like Monster with the sea invested like stone is for thunderclasts (titan of Water and the Coastal Regions)
• Cognitive shadow or corrupted Mandara spren or maybe Larceryn (if they fly) ---> Hurricane like Gale force wind, possibly invested with the power of storms and lightning (similar to storm form worn by the parshendi, Titan of Wind and Lightning)

I think this might be a possible explanation for Cusicesh, maybe he/she/it is a mindless remnant from the false desolation before the recreance, essentially a Monster with severed connection and identity, like dull form listeners. The Physical Realm manifestation of Cusicesh is just so creepy and so strongly mirrors the PR manifestation of the Thrill that something nefarious seems to be at play here.

I think it's going to be very interesting to see what the more ancient and powerful souls are that come from Braize, I like the idea too that there might be Titan like scourges that invest the 3 primary manifestations of the old gods of the Singers too.

 

[Wit Beyond Measure]

@hoiditthroughthegrapevine, I'm loving this so much!  Thank you!

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And the ability of certain creatures on Roshar to hold Investiture permanently, as Szeth says, rather than it seeping away like it does to humans.

Yes!  You know what holds Investiture really well?  (I'm assuming Stormlight is Investiture but I'm such a newb to all of this cosmere speak.)  Perfect gemstones like the King's Drop (and Honor's Drop or the Stone of the Ten Dawns) hold Stormlight for ages and ages and ages.  Perhaps that is part of the reason why they are perfect for trapping the most powerful Unmade.

Quote

The King’s Drop never loses its Stormlight. A stone this large should have run out after a month. It’s something about the crystal lattice, the lack of flaws and imperfections.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1065). Tom Doherty Associates. Kindle Edition. 

And then Celebrant:

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“At Celebrant, the moneychangers have perfect gemstones that can hold the light indefinitely. Similar [to the lighthouse keeper's globe].”

“Perfect gemstones? Like, the Stone of Ten Dawns?”

“I don’t know of this thing. Light in a perfect stone doesn’t run out, so you can give Stormlight to the moneychangers. They use devices to transfer it from smaller gemstones to their perfect ones."

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 927). Tom Doherty Associates. Kindle Edition. 

And then the connection to the physical realm:

Quote

Kaladin spent the time thinking about perfect gemstones. Did such a thing exist on his side? If there really were flawless stones that could hold Stormlight without ever running out, that seemed important to know. It could mean the difference between life and death for Radiants during the Weeping.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 927). Tom Doherty Associates. Kindle Edition. 

So Parshendi Surges without Stormlight probably actually come from the Stormlight they've stored in their perfect gemhearts?  And the floating natures of chasmfiends, skyeels, and greatshells might come from their stored Stormlight, too?  And are the mandras the spren for these animals that give them all their floating Surge?  Bonding with mandras grant the Gravitation Surge?

[+Hoiditthroughthegrapevine]

14 minutes ago, Wit Beyond Measure said:

So Parshendi Surges without Stormlight probably actually come from the Stormlight they've stored in their perfect gemhearts?  And the floating natures of chasmfiends, skyeels, and greatshells might come from their stored Stormlight, too?  And are the mandras the spren for these animals that give them all their floating Surge?  Bonding with mandras grant the Gravitation Surge?

Hmm, interesting, maybe the Fused after they have taken over the corporeal form of a Singer are only able to hold one spren in their gemheart, and maybe this is what grants them access to only one surge (like Leshwi only having the surge of gravitation). Also, I think it's been pretty clearly hinted at throughout the books that parshendi gemhearts are more effecient vessels for storage of investiture (Szeth mentions in WoK I believe), so that's one explanation for why the flying Fuzed never seem to run out of Voidlight, because there use of investiture is less leaky than the human equivalent. I think it's funny in the scene where Moash is going to talk to the High prince fused Hnanan that the flying fused float even when they are reading books, the casual use of investiture implies a highly efficient use for the primary surge:

Quote

Near the king's chambers, Moash passed two Fused reading books in the library. They'd removed their lengthy coats, floating with bare feet peeking from loose rippling trousers, toes pointed downward.

Makes me think that at night the flying Fused sleep like Dana Barret from the orginal Ghostbusters:

 

[Dlyol]

42 minutes ago, Wit Beyond Measure said:

So Parshendi Surges without Stormlight probably actually come from the Stormlight they've stored in their perfect gemhearts? 

Although irritatingly I can't find it at the moment there is a WOB somewhere that Szeth is wrong when he says that the Singers don't leak, they are more efficient but not perfect stores of investiture

1 hour ago, hoiditthroughthegrapevine said:

It is quite possible that great shells, with massive gemhearts, have held enough investiture to become cognitive shadows that can be respun out by the perpetual Odium desolation machine. If this is true, could those other more ancient and powerful souls waiting in Braize maybe be other greatshell spren/Cognitive Shadows capable of similarly creating Titan level monsters when bonding to one of the primary god substrates (Wind, Sea and Stone)?

 

OB states that those Fused which become Thunderclasts are simply the ones who have been most damaged by the process of becoming Fused. They are furthest along the line we see of worsening sanity amongst the Fused

Edit: Found it

Quote

 

Brandon Sanderson
Yeah, yeah like the cycle of water. And so just part of the way the nature of it works, it has to get out, it has to leak out, it has to run out. I mean it leaks even from spheres, right?

Argent
And when you lash things it's temporary--

Brandon Sanderson
Yep. And even though Szeth says that he thought Voidbringers could hold it they can't. Like it is just not the way that it works.

Argent
Can they just hold it better?

Brandon Sanderson
They can hold it better. It's not permanent. Now there are things that can do it permanently but--

 

 

Edited December 20, 2017 by Dlyol

[Wit Beyond Measure]

So which creatures are perfect forms of Investiture and thus hold perfect gemhearts?  Not Parshendi.  Not chasmfiends because the King's Drop was said to be as big as a chasmfiend's heart but perfect.  So...

1. Santhids?  Is that why they are so rare?  Or are Santhids really just chasmfiends that have been hunted, which is why they are rare?
2. Larkins?  They do love to suck it in, but are they good at keeping it?  (Just realized that the King's Drop thief is a Fuzed wearing a lightweaved disguise and exposed when Chiri-Chiri sucks off his Voidlight!)
3. Greatshells?  Dude, if greatshell gemhearts are perfect, then that makes Akinah (also known as The Rock of Secrets and The Void's Playground) in the Kaza interlude ever so important!  Important enough to have an Oathgate, which Jasnah believes destroyed (Pg 994 of OB).

When Kaza wakes on Akinah:

Quote

She awoke to a small cremling scuttling across the rocks near her. It had a strange shape, with large wings and a head that made it look like an axehound. Its carapace shimmered with dozens of colors.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 563). Tom Doherty Associates. Kindle Edition. 

Ooo, a larkin!  Perhaps the larkin is sucking up all of the Stormlight from the greatshell gemhearts, which are the very best sources of Stormlight since they are perfect like the King's Drop.  So it isn't that larkins hold Stormlight so much as eat it.  Rather, the larkins follow the greatshells around because the greatshells have the perfect gemhearts.  Maybe.

Quote

“After many warnings not to come to this place,” the cook said. “It is rare I must guard it so … aggressively. Men must not again discover this place.”

“The gemstones?” Kaza asked, growing more drowsy. “Or … is it something else … something … more…”

“I cannot speak,” the cook said, “even to sate a dying demand. There are those who could pull secrets from your soul, and the cost would be the ends of worlds. Sleep now, Soulcaster. This is the most merciful end I could give.”

The cook began to hum. Pieces of her broke off. She crumbled to a pile of chittering little cremlings that moved out of her clothing, leaving it in a heap.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (pp. 563-564). Tom Doherty Associates. Kindle Edition. 

Umm, so the cook transformed into dozens of larkins?  The larkins protect the secrets of the perfect gemstones to keep the worlds from ending?  Dude.

[Fourth Of The Night]

29 minutes ago, Wit Beyond Measure said:

Umm, so the cook transformed into dozens of larkins?  The larkins protect the secrets of the perfect gemstones to keep the worlds from ending?  Dude.

She doesn't turn into Larkins, she's a Dysian Aimian, which is a species that has a body made up of a huge number of special Cremlings called Hordelings.

[Dlyol]

38 minutes ago, Wit Beyond Measure said:

So which creatures are perfect forms of Investiture and thus hold perfect gemhearts?  Not Parshendi.  Not chasmfiends because the King's Drop was said to be as big as a chasmfiend's heart but perfect.  So...

My reading of the WOB is that no living thing can act as a perfect Stormlight store although I may be wrong. Certainly Chasmfiends don't because their gemhearts once extracted are very good but not perfect - my assumption is that the length of time it can hold it scales in proportion to the increase in scale (so a gem heart with twice the radius can store 8 times as much etc) but I'm not sure on that

[Wit Beyond Measure]

@Fourth Of The Night, thank you!  I vaguely remember now that the Aimians are odd, indeed! 

@Dlyol, so you don't think that Brandon meant we need to look for creatures with perfect Investiture when he said, "And the ability of certain creatures on Roshar to hold Investiture permanently..."?  I guess that could be.  So if not creatures, where would the King's Drop, Honor's Drop, the Stone of Ten Dawns, and the other perfect gemstones the Elsecallers guard be coming from?  Are they cut using Shardblades?  Thank you!

[Dlyol]

@Wit Beyond Measure My understanding is that the latter WOB supersedes the earlier one because in the second he says that the nature of the investiture is such that it cannot be perfectly contained whereas in the former he's talking more about the function of chasmfiends from a storytelling perspective and so I think he's being a little loose in his language (for example he says Szeth is correct in this one when elsewhere he makes clear he's not). On the perfect gemstones there's a lot of speculation they may be Dawnshards (I don't buy it) but it's the best theory we've got at the moment.

For reference here's the full WOB 

 

Quote

 

Argent

Awakening and Surgebinding, Stormlight and Breath seem really similar in some aspects--

Brandon Sanderson

Yes.

Argent

--except Breaths seem to stick to things better--

Brandon Sanderson

They do.

Argent

--than Stormlight. So when you are holding the Breath it doesn't expire when you put it in something it doesn't go away. Can you tell me something about why that's happening?

Brandon Sanderson

Part of this is kind of inherent to the Shard and the power it's coming from. I mean the power of Endowment is just going to stick, that's part of the nature of its magic. Does that make sense? But it also kind of has to do with how the ecosystems are working. For instance the Stormlight is essential to the ecosystem of Roshar, it needs to be expended, it needs to get out and-- It's like evaporation, does that make sense?

Argent

Recycling? Not the recycling but the cycle of--

Brandon Sanderson

Yeah, yeah like the cycle of water. And so just part of the way the nature of it works, it has to get out, it has to leak out, it has to run out. I mean it leaks even from spheres, right?

Argent

And when you lash things it's temporary--

Brandon Sanderson

Yep. And even though Szeth says that he thought Voidbringers could hold it they can't. Like it is just not the way that it works.

Argent

Can they just hold it better?

Brandon Sanderson

They can hold it better. It's not permanent. Now there are things that can do it permanently but--

 

 

[Rainier]

Quote

One crawled into the stone ground, somehow inhabiting it like a spren taking residence in a gemheart. The stone became its form.

This line, about Thunderclasts, is really striking to me. Since when can stone hold a spren?

2 hours ago, Dlyol said:

My reading of the WOB is that no living thing can act as a perfect Stormlight store although I may be wrong.

Nothing living, huh? But stone doesn't live, does it? What a thought, that stone could hold stormlight indefinitely...

3 hours ago, Wit Beyond Measure said:

“I cannot speak,” the cook said, “even to sate a dying demand. There are those who could pull secrets from your soul, and the cost would be the ends of worlds. Sleep now, Soulcaster. This is the most merciful end I could give.”

I interpreted this as the Dawnshards, which we know very little about. I'm attaching them to whatever the hell happened to Ashyn and caused the exodus to Roshar in the first place. Some artifact of great and mysterious power that's foreshadowed early so that way there's somewhere for the series to escalate in future books.

 

[Song]

This is interesting!

I might have missed something, but where do Thunderclasts come from?  Do they sleep in the ground and come back awake through Odium. Are they created at the moment of need from existing stone? Do they live in the ground under Thaylene city and Kholinar all the time and just wake up at the right time?

[Wit Beyond Measure]

24 minutes ago, Song said:

I might have missed something, but where do Thunderclasts come from?  Do they sleep in the ground and come back awake through Odium. Are they created at the moment of need from existing stone? Do they live in the ground under Thaylene city and Kholinar all the time and just wake up at the right time?

 They do come from a combination of stone and red-eyed spren that we can assume is of Odium, Voidspren.  We saw some in Dalinar's visions, and I specifically recall the one vision (Chapter 4 of WoR) in the Purelake where they were chasing a Voidspren that went into the stone and woke a thunderclast.

I speculate that there are gemstones embedded in the stone that the spren bond with to bring these stone monsters to life, like a golem.  Their physique makes me wonder if they are not the last stage or form of the chasmfiend given their resemblance to these creatures.

I'm not certain that thunderclasts can be raised anywhere there is stone and the right spren, but maybe.  The Shin do not walk on stone perhaps for this reason. I imagine very special spren are needed.  WoR calls the thunderclast spren "Sja-anat's spies."

I do wonder about Sja-anat.  She did tell Shallan the truth about the Oathgate, but she seems so very evil.  Is Glys a child of Sja-anat?  He seems trustworthy, right?  Even Ivory agreed that it was right not to kill Renarin.

[Song]

9 minutes ago, Wit Beyond Measure said:

 

I do wonder about Sja-anat.  She did tell Shallan the truth about the Oathgate, but she seems so very evil.  Is Glys a child of Sja-anat?  He seems trustworthy, right?  Even Ivory agreed that it was right not to kill Renarin.

Thanks for your answer, that is helpful! 

Spren seem to grow and change through their relationship with their host. Glys seems very genuine and good, but could that be Renarin's influence? 

Sja-anat seems to be changing, but as she is described as the most dangerous unmade I'd be hesitant to trust her outright.

Edited December 20, 2017 by Song

[Rainier]

13 minutes ago, Wit Beyond Measure said:

I speculate that there are gemstones embedded in the stone that the spren bond with to bring these stone monsters to life, like a golem.

There's some content I can't track down at the moment that speculates where gemhearts, naturally deposited by dying creatures, would congregate based on Highstorms pushing them around and burying them in crem. I hadn't considered that a Thunderclast would find a gemheart embedded in the rock and inhabit that, then use it to animate the rest of the rock. Great insight!

[.S.A.M.K.M]

Is it at all possible for a gem heart to be perfectly formed, or at least form in such a way that it mimics a perfect crystal? While it would be increadibly rare, it could be possible. It would explain why that place was scourged.

thunderclasts are fused that have lost control and sanity, that was the impression I received. So instead of taking a proper body, they are forced to instead take something akin to mobile siege weaponry, the fused can surge binding but thunderclasts just have their physical presence, they simply don't have the control or presence of mind left to use surge binding.

i am imagining, what if somehow all the fused were broken enough they could only have thunderclast vessel. While dangerous, not as much a threat as the sentient fused.

[Varion]

Thanks for putting all the effort in to pull all of these disparate pieces of information about gemhearts and their consequences, @Wit Beyond Measure. There are a lot of different paths to follow here, but I want to focus on Thunderclasts for a moment, using your original paragraph about them as a jumping off point:

On 12/20/2017 at 2:29 PM, Wit Beyond Measure said:

Thunderclasts

From the Thaylen City battle:

Quote

Venli got to watch the thunderclasts awaken.

Among the waiting spirits were two larger masses of energy—souls so warped, so mangled, they didn’t seem singer at all. One crawled into the stone ground, somehow inhabiting it like a spren taking residence in a gemheart. The stone became its form.

Sanderson, Brandon. Oathbringer: Book Three of the Stormlight Archive (p. 1090). Tom Doherty Associates. Kindle Edition. 

1

So the stone has gemhearts that, when inhabited by Voidspren, transform the stone into something else.  No wonder Szeth's people aren't stonewalkers, right?  Does stone have other forms?

I initially took your statement that "the stone has gemhearts" to be an error. Surely it's more likely that the stone contains naturally occurring gemstones (not gemhearts), which the Fused can bond with to create the thunderclast? But on reflection, perhaps 'gemheart' is the correct word after all. Specifically the buried gemhearts of dead chasmfiends. 

As you quoted above, we already have Adolin's direct observation that the thunderclast "looks like a chasmfiend. The head, at least. The body was vaguely like a thick human skeleton." Could this resemblance be because thunderclasts are formed when the Fused inhabit the buried gemheart of a dead chasmfiend?

To be honest, it was only after reading this thoughtful and well researched post by @MonsterMetroid that I made the connection between chasmfiend gemhearts and thunderclasts. MonsterMetroid's post takes this WoB, which discusses the possibility of gemheart "fossil beds", and expands on it, attempting to map the likely distribution of fossil gemhearts on Roshar. The main takeaway is that there are unknown numbers of gemhearts locked in the stone and crem of Roshar, and that their distribution is uneven, but potentially predictable. 

So, the stone of Roshar DOES contain gemhearts, and these gemhearts are still 'functional' enough to be worth mining by humans for use in soulcasting. They should therefore also be usable by the Fused, assuming that the Fused have the power to bond them.

That's still a pretty big assumption, though, and we don't have any direct in-world evidence for this, beyond Adolin's observations above. We don't have any clear WoB's either, although there are a couple of (mis-)statements from Brandon which, when read with this idea in mind, seem suspicious to me. The first comes from the WoB mentioned above:

Quote

Source

Questioner [PENDING REVIEW]

Is this world, assuming that [Roshar] is as old as it appears to be, wouldn't it be that the creatures that have gemhearts in them, as they die their body would rot away but leaving the gemstone? So wouldn't fossil beds exist with layers of gemstones in them from the passing of the ages?

Brandon Sanderson [PENDING REVIEW]

Yeah, that's why-- yes.

Brandon was totally about to dish something there, but caught himself. I can't help wondering whether it was something along the lines of "Yeah, that's why the Fused can make thunderclasts." Pure speculation on my part of course -- he really could have been about to say anything. But this second quote hints at a direct connection between chasmfiends and thunderclasts. The quote has already been referenced in this thread by @hoiditthroughthegrapevine :

Quote

Source

Questioner

What role will the chasmfiends play?

Brandon Sanderson

So there's a bunch of different roles for the chasmfiends that are all minor but-- For instance, I don't think anyone's made this connection, thunderclasts have chasmfiend-- it's part of the in-world inspiration for thunderclasts. And really chasmfiends exist in part to show off the symbiotic relationship between certain spren and certain creatures on Roshar. So when people who read the first book who know a little about physics can be like "Uhh, Mr. Sanderson" and I'm like "Well, look at these things that are flowing around this thing when it dies." It's an introduction of gemhearts and things like this. And the ability of certain creatures on Roshar to hold Investiture permanently, as Szeth says, rather than it seeping away like it does to humans.

(emphasis @hoiditthroughthegrapevine's)

Once again, Brandon seems to hold himself back from revealing some detail, before stumbling around for the more ambiguous "in-world inspiration" line. 

Now, take a moment and try to finish the sentence "Thunderclasts have chasmfiend ..." 

Maybe Brandon was going to go on to say "thunderclasts have chasmfiend gemhearts", and maybe he wasn't, but it sounds awfully plausible to me. I certainly can't think of any other word that fits better.

Assuming that this is correct, and thunderclasts do use buried chasmfiend gemhearts, then @MonsterMetroid's maps of gemheart locations in Roshar may have very big implications for future battles, given that natural process will ensure that some areas (such as the Purelake) are likely to accumulate higher densities of gemhearts over time.

Edited December 27, 2017 by Varion
clarity

[Wit Beyond Measure]

5 minutes ago, Varion said:

Brandon was totally about to dish something there, but caught himself. I can't help wondering whether it was something along the lines of "Yeah, that's why the Fused can make thunderclasts." 

Exactly!  I wouldn't say that they Fused make thunderclasts, though.  Rather, corrupted spren inhabiting stone-encrusted chasmfiend gemhearts become thunderclasts while corrupted spren inhabiting Parshendi gemhearts become Parshendi forms of power, most often Fused.  The thunderclast spren might be corrupted from Mandras, I would think, and the corrupted Fused spren were somehow from the souls of ancient Parshendi.

Rainier above seems to have also been talking about the same source telling about crem-encrusted gemhearts (buried in stone) leaving the opportunity for thunderclasts.

[Varion]

7 minutes ago, Wit Beyond Measure said:

Exactly!  I wouldn't say that they Fused make thunderclasts, though.  Rather, corrupted spren inhabiting stone-encrusted chasmfiend gemhearts become thunderclasts while corrupted spren inhabiting Parshendi gemhearts become Parshendi forms of power, most often Fused.  The thunderclast spren might be corrupted from Mandras, I would think, and the corrupted Fused spren were somehow from the souls of ancient Parshendi.

I still believe, like @.S.A.M.K.M above, that the thunderclasts are Fused that have been twisted so much of the centuries that they can no longer bond with the parshendi. We don't have a clear confirmation of this, only Venli's observation that the thunderclasts were formed by spirits who appeared to her as "two larger masses of energy—souls so warped, so mangled, they didn’t seem singer at all." 

The implication here is that Venli believed that they were the souls of singers (or parshendi), but twisted almost beyond recognition. I don't think we need to invoke another explanation unless you have some other evidence that suggests they were not originally parshendi souls.

19 minutes ago, Wit Beyond Measure said:

Rainier above seems to have also been talking about the same source telling about crem-encrusted gemhearts (buried in stone) leaving the opportunity for thunderclasts.

My apologies @Rainier! I somehow missed this post! Didn't mean to leave you unacknowledged for making this point explicitly before me. 

[Wit Beyond Measure]

Ah, yes, now that you've mentioned the Venli quote, perhaps the corrupted spren are the same corrupted spren that form the Fused rather than Mandras.  I was thinking Mandras because they have that same triangular head as well as the chasmfiends, but the head may just come from the fact that the gemheart is that of a chasmfiend.  Venli's quote certainly contradicts ordinary spren being the power behind these thunderclasts.  Thanks!

[.S.A.M.K.M]

According to the Parshendi song, it claimed the form of powers were made by the unmade. The thing is the unmade are not banished by the oath pact, so I wonder if they were formed after the pact was made.

the war could have started with just the heralds and the fused. But when the Knights were formed, this eventually led to the forms of power and the unmade.

from the description of the thunderclasts, it seems that is is the fate of all the fused eventually. I am hoping it is possible to accelerate the process. If only to spare the listerners having to sacrifice them selves to host them. 

My idea is to trap the nine in a fabrial and aim them at the fused. The more mindless and mental based unmade would warp them until they can no longer take hosts, while the others would remake them.

 

[Rainier]

@Wit Beyond Measure @Varion

Yeah, it was @MonsterMetroid, and the direct link is here, which I was referencing with the Thunderclasts/Gemhearts link. Props to him. I thought it was kind of a silly post at first, but it was thorough and I'm glad we can get some use out of it.

1 hour ago, Varion said:

given that natural process will ensure that some areas (such as the Purelake) are likely to accumulate higher densities of gemhearts over time

Forget future battles, we got our first look at Thunderclasts in one of Dalinar's visions. Where was he? The Purelake.

[Wit Beyond Measure]

32 minutes ago, Rainier said:

@Wit Beyond Measure @Varion

Yeah, it was @MonsterMetroid, and the direct link is here, which I was referencing with the Thunderclasts/Gemhearts link. Props to him. I thought it was kind of a silly post at first, but it was thorough and I'm glad we can get some use out of it.

Forget future battles, we got our first look at Thunderclasts in one of Dalinar's visions. Where was he? The Purelake.

Yes, he believes himself to be in the Purelake.  And there's something terribly strange about the tower there, as well:

Quote

The group ran toward some kind of large rock mound ahead, shadowed in the dusk. Maybe this wasn’t the Purelake. It didn’t have rock formations like—

That wasn’t a rock mound. It was a fortress. Dalinar halted, looking up at the peaked, castle-like structure that rose straight from the still lake waters. He’d never seen its like before. Jet-black stone. Obsidian? Perhaps this place had been Soulcast.

“There’s a fortress ahead,” he said, continuing forward. “It must not still exist— if it did, it would be famous. It looks like it’s created entirely from obsidian. Finlike sides rising toward peaked tips above, towers like arrowheads . . . Stormfather. It’s majestic.

Sanderson, Brandon. Words of Radiance (The Stormlight Archive, Book 2) (p. 73). Tom Doherty Associates. Kindle Edition. 

Fins and arrowheads?!!  This fortress sounds like it could have been created through a gemheart bond, just like the thunderclasts (and possibly Urithiru though Urithiru doesn't seem to resemble any creatures).