Yata

I think you are mixing effects together...Dai.gonerthis isn't the Unmade related to Death Rattle, Moelatch is the Death Rattle's one. Returning to Cusicesh and his possibly "Unmade" status...this would be weird, it's a Spren struck there from years (at least), if He is an Unmade. It would be the easier Unmade to track down, I find strange that Spren's comunity, the Stormfather or the remaining order didn't place it in some kind of "isolation" (if its descruction isn't possible)

We don't know what Attributes the Chimeras' Spike had, neither if the Spikes some guys (I will not tell more to avoid Spoilers) had were made of Trellium or mundane metals (I think they will use Trellium to avoid Harmony's interference if possible). Notice also that Atium could steal all the attributes and better than any other metal (less initial lost) this give him an uniquie propriety. But actually we don't even know if what we call "trellium" is a pure godmetal or a godmetal alloy so any proof and counter proof is probably far to be meaningfull

I am working to the Unsealing trick too. I had to say that Harmonium as Unsealing's trigger isn't a solution I lke. But honestly I failed to every ideas that come to my mind: - Nicrosil is auto-unsealed because the Investiture isn't converted into other kind of things: We have a Wob quite aganist and much more, this would mean that other kind of Attributes are auto-unsealed - Faulty Nicrosil to allow the charge to leak out: No Wob points to a Charge leaking if the metal is a bad metal...and the Bands will not have yet their powers after all that time. Returning to Harmonium as trigger, It's not a Sanderson's habit to explain something in detail (Medallion's structure) only to have an "hidden spot" with weird function. Wax himself took time to check the medallions...He didn't find some strange metals and if we work on the assumption that the Harmonium need to touch you, it's weird. PS: Thanks to point me to the Discord server. I didn't know of its existence

The only solution to this problem is that Nightblood turns Investiture into unusable investiture or ruin it so deeply to need a very long time (in a Cosmere scale) for the Investiture to be avaliable again. So over time Nightblood's consumed investiture will grow bigger and bigger

Like I said before I don't think Lerasium works as universal Metalmind...but your logic about the useness is quite a no sense to me. The Metals don't need to be at the same level. It's not a game where the powers need to be balanced because for the game's sake. It's possible that a metal is quite useless, because for Realmatic reason, that godmetal have to work in that way into a specific magic system.

But maybe the ancient Terrismen already know advanced Feruchemy's applications (like unkeyed Metalmind) and we know Hoid had contact with the Ancient Terrismen organization

Except you have "carry it" below the Spiritual Realm, where the difference matters...Probably in the Spiritual Realm actually all Investiture is the same, but Investiture isn't only Spiritual, it extends beyond the Spiritual Realm. If you could change the "other parts" You could take Ruin and turn it into Preservation (The whole Shards not bit of powers)....Odium will not leave the defeated shard, instead He would turn the loser's power into more than his own.

The problem here, is that as far as we know change Preservation's Power into Breath is turning Preservation's Investiture into Endowment's Investiture. A feat probably not even the Shards could manage to complete.

thanks @Pagerunner it's a bit extreme for the purpose I need (a bit off alloy) but it's indeed interesting and probably the best WoB I could find on the matter. I may use it as base for minimal change in the alloy (something that happen for sure when you pass from a good metal to another). The idea was to see if a "bad metalmind" leaks his charge...It was a possibility I want to value for the Unsealing of Metalminds. The WoB seems quite clear...the Investiture remains there but unreachable

All the Allomantic Powers work to a certain extent into all three realms, but they are mainly focused to manipulate one of it. For example (and this is aganist @The One Who Connects said): Emotional Allomancy may propagate into the Spiritual Realm (also if the distance seems to affect it so it's weird) but edits the subject's cognitive and forces the brain and the body to accomodate to this change (physical change)...But it's mainly Cognitive in its working. The same thing with Steelpush/Ironpull, the Steelines are Spiritual in nature but they allow you to influence the target's physical...so the metal is mainly Physical in his working.

@Spoolofwhool I remember quite well someone asked to Mister Sanderson if the " Linchpin Spike" need to be an F-Gold gifting Spike, and he replied he doesn't need to be a F-Gold one (not the actual wording). This point to a "the Linchpin needs to have a Spike to connect the Hemalurgy's modification but the Spike would be any kind of Spikes"

Yeah it was that WoB, I tried to search with "metalmind" and "feruchemy" without success, thanks I disagree, the no logical scale may mean a lot of things: It is possible that you have two equal iron rings (I will use Iron for an easy access to the attribute) filled until their limits, then I forge the two rings together and their ability to hold charge is more than their previous capacities together. This is probably the reason for some relative small objects to be able to keep an huge amount of charge (The Bands for example, but I will point to other high invested object in the Cosmere). As the metal's mass or volume become greater their Feruchemical's size grows faster than linear.

I have a doubt, we know the Metal's structure is really important in the Metallic Arts and their Efficiencies is linked to how much a metal is near the "perfect structure". We know what happen when you try to burn a bad metal (less power output and some bad effects on allomancer body). But what happen if you try to use a Metalmind made by a bad alloy ? There is a Wob about ?

Nightblood is an attempt to create a Shardblade using the Nalthis Magic....and indeed Nightblood is a type of Shardblade, an unique type build with a different kind Magic. She is actually like a "robot-spren" or "frankenstain-Spren" made by 1000 Breath and possibly other kind of Investiture. In Realmic Theory the "living investiture" is called "Splinter" and Spren, Divine Breath, Nightblood and other beings are actually Splinters. Nightblood is an artificial Splinter created by placing together Investiture and forcing them to gain self-awares througth Awakening. There are theories about the reason of Nightblood's creation and working. But for now they are only theory so I will avoid to place them here in an Q&A topic.

Notice that Compound isn't a istant task, you didn't obtain all the Compounded's charge in a big flash...You still burn it with your Allomantic Strength so you need time to burn all the metalmind. Probably you will feel something wrong and stop compounding and if you continue fainting for some kind of shock (to sugar in the blood) before he reach a lethal point.

I can't remember the wording but someone asked about Metalmind's capacity and Bradon said it's more complex than you could think....So I think the "linear scaling with the mass or volume" isn't really an likely option. I will try to find this WoB but I remember only the general sense and of course I store Informations in another language...this is the reason I have problem to find old WoB also if I remember them

I think it's better to avoid to set the Feril with a relationship on the amount of charge to fill a specific metalmind's size. First of all we don't know if different Feruchemist has different limits (a theory is that a stronger Feruchemist could fill a Metalmind more), lastly from a WoB seems that a Metalmind's capacity isn't linear with its mass/volume

You see it, when Vin burnt it..She see the GoldShadow of TLR and an Inquisitor. If you prefer something more official

Well not really, for example Malatium (the Eleventh metal) is a god metal alloy (Atium+gold) and it works simply as "Gold on others". The Lerasium (another godmetal) work rewriting the Soul (so a Spiritual effect)...there are of course ramification for this, but its effect is spiritual @Secrets I know it is an uncool solution, but a prepared team may overcome the friction problem with a simple and mundane aerodynamic shiled.

I don't know if it is relevant but acutually "the Power of Creation want to be used" and it need a mind to direct itself...so if a true mind isn't avaliable it try to develop one of its own.

The Temporal Quadrant of Allomancy seems to be deeply Spiritual more than Cognitive as the future sight (as the past sight) is Spiritual dependant. You don't see "how you view yourself" you simply see an "alternative you"....you may notice as TLR hardly see himself like an happy packman (both for the happy and the packman). Anyway I am unsure about your idea of Gold+Durallumin as a way to worldhop...but indeed is interesting. The only counterproof I could provide is about Elend and his Atium+Durallumin who simply give to him a real Future sight instead of carry him in the Cognitive. He could simply run/use other fast travel to get there, he didn't need to worldhop to performe this feat...but this is tangental to your theory

It's all a matter of how much a being is in relation to the realms (i like to see the realms as different floors and every being as an elevator between the three floors) . To say if you go on the Cognitive Realm, you may punch a spren (and a Spren may beat you of course) If the Spren extends itself fully in the Physical realm he may interact with regular matter (you may hold a Shardblade after all). The same thing happens with Lift, She is deeply in the Cognitive than any other physical being we saw...This allow her to touch cognitive entities (I just imaginate Lift tring to hug the Stormfather...) and it's probably the reason of her other weirdnesses

Because Lift is more in the Cognitive Realm than standard Humans and may interact with it more. Notice it's not an unique case, you see all the time objects interacting with other Realms, The Shardblades for example cut the Soul

As I said you gain "only" more Charge than the one already there, and it's not a little gain. It's possible, but honestly there isn't any clue about. And indeed is a strange effect for the Feruchemical Lerasium...but as I said there isn't an answer to that. EDIT: please avoid to post, multple posts, edit the previuous if you forgot to write something ;-)

Funny fact: There is a guy in America (I know a bit vague, but I read this story many years ago) who is actually a god. When he was only a baby traveled with his family in Africa for holydays...in the visit they lost some objects, within this objects there was a photo of this child. A tribe with almost no contact with the rest of the world found this photo and they thought it was a relique (they never saw a photo) and the one on it was a god....they workship him for years until a antropologist discovered the fact and track back the guy...For all this years the boy (now a man) was that tribe's god.