Trusk'our

We already have examples of the Malwish airships somehow using iron Feruchemy to lighten themselves, so extending this to an object with a semblance of its own Intent is not unlikely. BoM, pg. 401-402 So unless the Awakened object to too stuffed full of Investiture (like Nightblood) I think it's very plausible Feruchemy could be harnessed by them with the right setup.

It does seem that way a little, doesn't it? I always found its nature closer to that of Ruin, given the leaky black Investiture associated with Ruin's Intent, the stealing of Investiture through destruction (ahem, Hemalurgy anyone?), and the Command to "Destroy evil". In fact, we do have a WoB on this, and though it's a bit shaky as to its exact implications I take it plus the aforementioned hints to suggest that Nightblood corrupt any Investiture it consumes to align with Ruin's Intent more.

Happens to all of us

Aluminum Feruchemy manipulates Identity, while Feruchemical duralumin affects Connection.

Alright, so Honor, Cultivation, and Odium all had a finite amount of Investiture that they could bestow upon their servants as per their agreement. But later, Honor comments on how he granted the Heralds access to more of his power, though the Unmade are specifically mentioned to be stronger because Rayse didn't Invest the Fused as greatly. I had assumed that Honor had already given the maximum output of Investiture so that his forces could be at full power. Was this just an incorrect assumption, or were the Heralds perhaps just given more laxness in their bindings and not more Investiture? But, Honor really, really wants to keep oaths. How could Tanavast lower the Heralds' inhibitions if the Shard was following an agreement to bind them in order to prevent a potential cataclysm? I might be approaching this the wrong way, and I'd like to hear others' thoughts on the matter. One final thought- do we have any guesses as to what Cultivation was doing with her (presumed) extra power? The Radiants all have pieces of both Cultivation and Honor, but the Heralds are only of Honor, which probably leaves a sizable portion of Investiture left over for Kor to use as she wants. I'm sure the Boons/Curses fall into this usage, but most people who bear them probably die eventually and that Investiture eventually recycles back to her. Does Cultivation have something else she made up her sleeve, perhaps?

Note that silver does not destroy Investiture, but merely disrupts it for a short time. It's deadly to things like Shades, but Spren themselves would only be "killed" for a short time before reforming.

Glad I could help! (Also, if my answer was sufficient, would you mind checking my answer as correct? It's right by the upvote/downvote button)

This is not correct. Feruchemical Atium merely changes your physical age, not even the Spiritweb. It isn't restoring you to your natural state, but actively fights against the Spiritweb. Gold Feruchemy/Compounding was used in conjunction with Atium for TLR's immortality. If Atium had other Feruchemical uses, Sazed would have certainly known, as the Terris had already experimented with the metal.

Yes, Lift could indeed take the calories from Bendalloy Compounding to generate Lifelight, though Brandon has admitted that it's a somewhat convoluted process.

It would indeed be easier to Awaken an inorganic object that was Soulcast from something once alive, as the Spiritual Connections would still be intact. But note that if the object is already Awakened that your Soulcasting will need to fight through the extra resistance, which is very inefficient. So, if it's already Awakened perhaps it will be cheaper on your Breaths expended, but the Soulcasting part will be substantially more difficult, maybe even impossible for most practical purposes. If you wait to Awaken until after Soulcasting an organic material, things should work much more smoothly.

Question: what is the limit to a single ability? If I choose Breath as one of my powers, do I get only one Breath, or can I choose the God-King's hoard? If I choose Surgebinding, can I choose a Bondsmith's spiritual Adhesion? Can I choose a biological ability, such as a Singer's Spren bonding ability or a Kandra's shape-shifting?

By era 3 there will be at least three Godmetals available for experimentation, four assuming a pinch of Lerasium is made and Marsh can spare a bit of Atium. Most are still very, very rare though, so experimentation should be done as efficiently as possible. First, when making Godmetal alloys, DON'T use them for Allomancy first. All known Metalminds are 100% recyclable, and alloys use the same percentages as Allomantic and Hemalurgic use. Second, keep at least one super-Seeker on staff to listen to the Pulses emitted when using the metals. Vin was capable of innately understanding Breeze's Allomancy in WoA (chapter 20, I think, though I can't find my copy). Doesn't matter if it's done through a Nicroburst, Hemalurgy, or some form of Harmonium, it's worth Investing in so you can get an even better idea of what the new Investiture is trying to do. Other suggestions to experiment and discover uses with Godmetals?

True. I'd actually argue that Breath does grant sentience, as inanimate objects Awakened are capable of sensing and interacting with the world around them in a meaningful way and even Awakeners have their perception changed and enhanced. Sapience not being granted (most of the time) makes more sense though, as it doesn't give a lot of higher cognitive functions to type III and IV BioChromatic entities. That would probably be the best route to take in granting true sapience to an animal, though I'm sure Elantrians can do it too.

To nitpick, I'd argue Kandra don't get warped probably because they're shape-shifters, so they simply sidestep such phenomena. Regardless, their power is ground for Hemalurgic Investiture that doesn't necessarily need the body to change to use attribute spikes (it isn't concrete given their unique interactions, but at least worth taking note of). I think so, yes. I was mostly reasoning along the lines of using an alternative source to fuel Feruchemy (that isn't Compounding) that did not require you to sit a Feruchemist down and actively weaken them to charge a Metalmind. Spiking a person to get the necessary attributes instead of just using the person. . . well, it doesn't really quite follow through with this original idea but once done you could theoretically drain the spike round the clock without needing a human host. Just hook up a spike for centuries to come, maybe fueling spike production with the dying, perhaps use F-gold to regenerate lost Spiritweb fragments, or maybe just take tiny, tiny slivers from many people.

Leeching seems to only affect kinetic Investiture, but not static Investiture. Otherwise, whenever someone got Leeched they'd become a Drab. Mr. Suit had most likely only used his chromium in a short burst to remove Wax's stores, as it burns fairly quickly. So, in theory had Suit kept burning I think it would have prevented Wax from smashing them both through the bottom of the airship, but it wasn't the tactically sound thing to do (as far as he was aware at the time).

@AirsickAviar, I started up a thread here (F-zinc uses and questions) that dives into the user's experience with zinc and what it can actually do for you. My personal takeaway from the discussion was that zinc Feruchemy primarily focuses on increasing one's intuitive ability to understand and calculate the world's workings, though this shouldn't do much to change the actual solution you dream up. In other words, it changes time and effort to understand something, but doesn't strictly alter your intelligence (though some outlying feats such as Sazed predicting where a projectile will land are also boosted, so perhaps this isn't quite accurate). I think this is still massively powerful though, as someone with extra mental speed (from Compounding or blank Metalminds) can not only leverage what they currently know more quickly and readily than a non-Sparker, but they could also learn and add to their knowledge with greater ease too.

Since apes and humans have such a similar anatomy, yes, I am fairly certain bindpoints would be very similar too. Also, since a weaker mind makes a construct more susceptible to Allomantic control (see Koloss in Era 1 and TenSoon's Blessing countering some of his weakness), I think Hemalurgic apes would be easier to dominate than humans with spikes. Don't know about controlling spiked Lifeless with Emotional Allomancy, but I suspect they'd at least be easier to break than normal Lifeless as an Awakener. And perhaps Emotional Allomancy can make it easier too, as Lifeless are effected by it in some way (I actually suspect it's similar to Command breaking or controlling a Hemalurgic construct). I don't think so. Breath is basically just innate Investiture that can be given to others and shaped a little through Commands, but you couldn't give something like a Mistwraith sapience with it. Now, if you juice then up to Nightblood levels I think you'll see a real cognitive enhancement, but that's not exactly cost effective.

I need to re-read all of Mistborn. It's been too long, really

I mean, there are Unsealed Metalminds with two powers in BoM already, and Allik mentions the existence of some with three. Yup. Really, a more helpful thing here would be a kind of formula for determining Resonance effects, even if it's loose. Then people could dive in all they wanted for years to come.

Excellent question. Corruption seems to occur when an Investiture is actively co-opting control over another manifestation of Investiture. Soulstamps are a good example of Investiture corrupting the Spiritweb of a person. However, it can't just be two Investitures merging together, as Warlight doesn't manifest corruption despite being comprised of two sources, nor does Harmony express corruption despite bearing two Shards. WaT spoilers: So perhaps an invasive, forceful Intent is necessary for it to count as being corrupt.

I mean, he certainly would have a Resonance (probably his outrageous Fortune/luck), I just don't know that he'd have a hybrid power like some Radiants have. This is true, but you can squeeze in a few extra without it being an issue and can get new Resonances from it. Really, it just struck me recently that the hybrid powers are what are especially interesting for artificial Metallic Arts, since there are so many ways to mix and match powers.

In Surgebinding we see that two powers in one vessel begin to change one another. Bondsmiths and Windrunners both share Adhesion, Lightweavers and Truthwatchers share Illumination, but they are manifested in different ways. Not only that, but the two powers can be used in concert to create a new effect, such as Illumination and Transformation Substantiating Lightweavings, Adhesion and Gravitation creating a reverse Lashing, etc. This isn't limited to natural powers either, as Szeth is fully capable of using a Reverse Lashing with Jezrien's Honorblade. So, what if you combine two or three powers in an Unsealed Metalmind? Could you not only change how the powers manifest, but perhaps combine them to generate an entirely new (but closely related) ability? For example, let's say you have an Unsealed Metalmind that bears both Feruchemical zinc and copper- the power to quicken your thoughts and to save memories by putting them in a Coppermind. Maybe together they could better process retrieved memories, or perhaps create multiple strings of thought simultaneously? Later you add Allomantic zinc to the Metalmind's repertoire. Perhaps this adds a slight enthusiasm during the process, all together making learning and general cognitive augmentation far more powerful than with any of the individual powers on their own. I doubt every power combination will lead to something new, as Wayne doesn't seem to have a hybrid power like how Wax's steel bubble might be considered one, but it would still be very interesting to see the Metallic Arts develop new powers by essentially alloying Investiture.

Yes, you are sadly insane. But yeah, that reasoning makes good sense. Eh, I mean, it's still affecting kinetic Investiture, even if it's not coming from a metal. I don't know if I'd completely discount one's own Spiritweb as long as you're currently drawing from it. I'm not at all confident in my suggestions though, as we haven't seen Feruchemy affected by duralumin or nicrosil Allomancy yet. More I was just musing on hypotheticals for a Twinborn with an interesting combination of powers.

So, it's possible for Allomantic nicrosil and therefore presumably Allomantic duralumin to affect Feruchemy as long as it's kinetic. And of course, storing Feruchemical attributes makes them kinetic, as Dumad can sense Wax reducing his weight in TLM. I'm guessing that tapping attributes while burning duralumin will just make you tap them all at once (it's also been proposed to reduce the compression loss of such high tapping). But, what if you try burning duralumin when storing? If your entire attribute becomes targetable by duralumin, you might just die. Brass would freeze you, pewter would make you so frail your bones snap, and gold might just make you fall apart. Or, perhaps if only the only the small portion of the Spiritweb being actively siphoned off is considered valid for Allomantic duralumin, it might be slightly safer. If the act of storing an attribute is akin to Hemalurgy at all, the added force might actually rip off a portion of the Spiritweb associated with their Feruchemy. Maybe making something like a Hemalurgic spike, but no Ruin involved? If the storing attributes works where the siphoning of Investiture from your Spiritweb pulls more from the surrounding SR, making it a kind of conduit, maybe burning duralumin while storing an attribute would make the process faster? Kind of like Compounding, but through a different method and being harder on the Twinborn. Lots of weird interactions, potentially.

You know, I'm not sure how to compare Harmony, Retribution, and the Dor. Retribution has higher ended MoIs and especially noticeable chunks of Investiture put into Unmade, Heralds, the Sibling, and the Stormfather (and given Syl's new appearance after his destruction, I think now her). However, Ruin and Preservation made an entire planet from scratch even if their MoIs are generally not very high scaling. The Dor's powers seem to be channeled by mortals like no other Shard(ic pair) except maybe Bondsmiths, what with Elantrians being more Invested than Returned and Elantris itself being a giant magical conduit. I think that there could be arguments made for any of them being the most Invested, though that difference probably won't be substantial.