Spiritual realm bleed through...?

[ArmbarBanker]

We know that there is something different with Threnody because of the bleed through to the connotative realm and the planet. If I remember correctly in, Secret History,  a section of threnody was in the cognitive realm and that is what caused the shades to be visible in the physical realm on Threnody.

 

 Has anyone found or believe to have found similar bleed through with a planet and the spiritual realm?

Are there any theories on why Threnody is special?

[Calderis he/him]

I seem to have totally missed something, because I don't understand where any of this information comes from... 

[CaptainRyan he/him]

2 hours ago, ArmbarBanker said:

a section of threnody was in the cognitive realm

Perhaps I am misunderstanding you here but, as far as I know, all the sections of every planet (Threnody, Roshar, Scadrial, etc.) are represented in the Cognitive Realm. In Secret History, we see Kelsier travel all over the Final Empire (and beyond) in the Cognitive Realm.

So, assuming you already knew that, this means you meant something else:
1) If you meant the fortress we see, that is not of Threnody. You probably do not mean this.
2) Perhaps you are referring to the Ire being worried about the Shades crossing over from Threnody. In this case, as far as I know, the reason the Shades are a threat to the Ire is because the Shades exist in the Cognitive Realm and can wander far enough to reach the fortress and cause problems. It has nothing to do with, again as far as I know, a portion of the Physical Realm of Threnody bleeding into the Cognitive Realm.
3) Something else?

If you do not mind clarifying a bit what you meant by "a section of threnody [sic] was in the cognitive realm [sic]" then I think that would help us theorize with you better. Cheers!

[ArmbarBanker]

I was referring to the shades crossing over from Threnody. I must have misunderstood that section thinking that this meant there was a section of the cognitive that was bleeding over to threnody. The Ire were more worried about shades from Threnody then any were else and I took that to mean that the shades were stuck in between the physical and cognitive realm.

Edited June 12, 2017 by ArmbarBanker

[Spoolofwhool]

1 hour ago, ArmbarBanker said:

I was referring to the shades crossing over from Threnody. I must have misunderstood that section thinking that this meant there was a section of the cognitive that was bleeding over to threnody. The Ire were more worried about shades from Threnody then any were else and I took that to mean that the shades were stuck in between the physical and cognitive realm.

From what I recall, the Ire never actually said shades, just Threnodites, and my interpretation of that was that they were afraid of worldhoppers from Threnody from coming over. Furthermore, I think it would be difficult for shades to wander all the way there, near or in Scadrial's region of the Cognitive Realm. As some form of cognitive shadows, they would likely be maintained by some investiture connected to Threnody. This would make it hard for them to leave Threnody. 

[Blightsong he/him]

7 minutes ago, Spoolofwhool said:

From what I recall, the Ire never actually said shades, just Threnodites, and my interpretation of that was that they were afraid of worldhoppers from Threnody from coming over. Furthermore, I think it would be difficult for shades to wander all the way there, near or in Scadrial's region of the Cognitive Realm. As some form of cognitive shadows, they would likely be maintained by some investiture connected to Threnody. This would make it hard for them to leave Threnody. 

Quote

“Well,” the captain said from behind, voice echoing. “Nobody from Threnody within a day’s march of here. Looks like a false alarm after all.” Kelsier hesitated in the empty corridor. Then, cautious, he crept back to peek into the room. The guards and the wizened creature all stood around the device, seeming displeased. “I do not doubt your foresight, ancient one,” the guard captain continued. “But I do trust my forces on the Threnodite border. There are no shadows here.”

They seemed to be talking about Shades.

[The One Who Connects he/him]

I interpreted the line as implying the withering effect of Shades could kill them, so they are being overly cautious for personal safety, rather than implying any deeper meaning about the realms themselves

[+Lewis Nethur He/Him]

Back to OP's original questions, something to bear in mind is that most (all?) things in the Cosmere exist in some capacity in all three realms simultaneously.  What you describe as "bleed through" between the realms is the phenomenon known as perpendicularities; places where all three realms "intersect" so to speak.  At these intersections, weird things are possible due to the concentrated Investiture; people (or things) that normally exist primarily in the Physical Realm can transition their presence almost totally to the Cognitive Realm.  We've seen characters poke their heads into the spiritual realm as well, however, the breakdown of time and space in the Spiritual Realm make it a rather silly place that isn't conducive to long writing stretches; We've only seen characters briefly look around, gain a bunch of futuresight, then leave before they could be driven completely mad.

What makes Threnody special is that, while it has no stable perpendicularity, one or more of its manifestations of Investiture cause unstable (possibly short-lived/temporary) perpendicularities to pop into existence; it's implied that this has something to do with the shades, though it's also left deliberately vague.  Shades actually tend to stay close to where they were created, implying that they have strong location-based Connection which would make it very difficult to leave their system under normal circumstances.

The existence of many unstable perpendicularities on Threnody could mean that Worldhopping off Threnody is very easy if you know what you're doing.  Since Threnodites possess relatively advanced technology (gun powder, and we see Nazh use some kind of horrifying ghost-gun weapon on Scadrial), their homeworld totally sucks, and it might be easy for them to marshal a large number of people into the Cognitive Realm in relatively short order, it's possible that the IRE are worried about Threnodite invading other planets or attempting to settle Cognitive lands they considered to be within their domain.

From what we've seen of Nazh's horrifying ghost-gun thing, it's entirely possible that Threnodites have found a way to weaponize Shades, which would definitely upset the IRE.

[Weltall]

We also know that Khriss has tried to petition the Ire for knowledge and they've rebuffed her. We don't know when this started but she was obviously aware of their existence during the time of Secret History so it's possible that one reason for the Ire's focus on a 'Threnody Detecto-matic' (if not the only one, this sounds more extensive than that) is that they're keeping an eye out for Nazh. He's Khriss' go-to for James Bond missions and the Ire have good reason to be especially cautious at that particular moment; Nazh showing up could have been as troublesome as Kelsier ended up being.