Yata

Yeah pretty all the mondane matter is made by the same amount of Investiture I suppose. If R&P creates Scadrial at all, the only thing different is about the Intent of the Investiture used.

I finished SoS just some hours ago. And as I understood about Lessie's Death, Harmony made her move (She may be controlled by the Spikes) and Blood Tan (He met Marsh and probably He gave him some istructions) react as Harmony told him to do. Of couse my interpretation can be wrong

Maybe the Spren Bond on Roshar make possible to use the specific "Aon" in a more intuitive ways...something like "use less modificator" or something like that. PS: I had a theory about the power gifted through bond on Roshar (it was about another kind of Human-Splinter relationship) but I don't know if we know something new information to confirm or deny it.

Maybe Hoid tries "just" to rebuild some Adonalsium's Investiture through the merging of Shards' Investiture. The Harmonium will be a great sample because it come from the Only (I think) Double-Shard in the Cosmere. It's like to find naturally a clue to your own reserch. You may progress very fast with that.

Investiture interferes to other Investiture, therefore maybe a Drab meets less problems to cross between the Realms than a regular Human (and a Nalthian Human with his single Breath have more problems).

Maybe Adonalsium himself dying Splintered his power to avoid someone else to held it. Or maybe the "Status" of Adonalsium's power required some kind of "balancing" from his Holder and when He died, simply the power can't remain a whole.

Yes, it was a speculation of mine, I didn't say it was sure. Just a little point, in my model the Stormfather is the outcome of an Adonalsium's Spren (Rider of the Storm) merging with Tanavast's Cognitive-Shadow. If this is the case, Rider of the Storm (and the Stormfather) is very compatible with Stormlight (as both is quite Adonalsium-power).

Wow great news, we may exclude a Divine suicide now.

If you ask about "Odium's Magic System on Roshar" probably as H&C's ones: Odium's power manifest itself like Splinters bonding as parassite with influenced being (the Listener's Form of power) and with powerful Splinters (Unmade) manipulate the Roshar's people with more limits but also more range of target. (I immagine them like an Odium's Nightwatcher). While if you ask about "Odium's Magic System on Braize", I suppose nobody may answer it, we don't know quite nothing on that Shardworld and how the magic arise on it.

You caught my point pretty well and reading your post I understood your point better (also if I don't agree with it). But there is something I can't undertand: You discard the Focus-Concept because you find it useless as predictive tools. But to removing it, you add to the Standard model of the Magic Systems (I don't know, have we a better term for the deep mechanics of Magic Systems as a whole ?) exceptions to explain some phenomenoms. You call them oddities (for example the Metal-Blindness of R&P) but isn't it a counterintuitive replacement to a more linear explaination ?

If you have some knowledge of Hemalurgy (I don' know how they may obtain it). Everytime an Allomancer are born, you "sacrifice" him and his power may use for the Society forever (in theory). Of couse you need a way to stop the Decay but form other topics, someone says that a way to stop the Decay is known (but it is from books I didn't read still). The Allomancy is very rare in nature but in a 1000 years and with enough people you may create a decent amount of Spike, and maybe you may use more Spike of the same type to emulate a single powerful Spike.

But we don't know if Surgebinding off-world works in the same way or if it is something like "as a Seon may actuallizate his Aon, A Radiant Spren may actualizzate his Surge".

But we know that the "focus" is something that affects the Shards itself (for example R&P have Metal-Blindness) therefore it's not something "for Mortal only". There is something that deeply link Investiture and Focus, also without "magic users" The Magic systems at all aren't the power of the Shard, The Shard may use as he want (with the Intent limitation of course), but in any Shardworld "something" (probably in the Spiritual Realm) spread the Magic in the Shardworld at all. And the magic System are "naturally built" from Shard's Investiture and Shardworld's Focus. You may call it "Focus" or "Investiture's Gateway" or "Access" but is pretty a Semanthical problem. I will avoid to call it "nozzles" because this word is useful for the External Magic System only (ex: Allomancy, AonDor) where you are linked to an unlimited Source and the focus works like both "Access/limitator".

"more powerful" and "more invested" aren't the same with two effects that working in different ways. Nightblood may be more invested than a spren (or less or equal), but that isn't a proof. We also know that Nightblood has an "unbalanced" (without a better word) power and his Investiture isn't enough to keep his full Power and his full mind at the same time (while a Radiant Spren may do it).

But my main point was that the Stormlight isn't H&C investiture, but natural Adonalsium's Investiture

Everything is made of Investiture. The things that we call "Invested" is above this "standard level of Investiture". The Atium probably is only "matter made by only Ruin's Investiture" but not "high Invested" therefore there isn't probably a lot of Interference. The Alluminum is an "oddly" case in the Cosmere and creates problems in many Magic System (not all of them), until now we didn't understand the reason (but there is some theory in this regard).

As Natc says we don't know how much Investiture a spren has. If We try to compare the various Splinter and say that Endowment's Splinter (Divine Breath) is as invested as a Radiant Spren (no proof at all). We may see how a Splinter (a Divine Breath is at least 2000 Breath worthy) is more Invested than Nightblood ("only" 1000 Breath)

But the Spren needs to bond another Radiant to keep his mind and warn someone

To be honest I don't understand what you want to say :S

But the Aon Omi and the Teleport of Drahkor are specific task in the whole Sub-Magic System. It's possible that exist an Aon near to Dominion and a Drahor's Power near to Devotion. Simply they didn't usually (or at all) use them

Well not for nothing the God-King has a Treasure of Breath .... It's possible that in the capital there is more Breath in him than in the rest of the population together

Nobody dies to craft Nightblood, therefore there isn't any Divine Breath in the Blade. A fresh WoB (from the BoM release party):

He is watching us

I know there is a WoB about, but at the moment I have no time to find it. Later I will post it.

Just a point, the "Standard Shardblade" slice the soul (or Spiritual if you prefer) not the Cognitive. Nightblood instead cuts in all three realms