Trusk'our

Flesh Forgery, or Resealing as it's known by the Grands of the Rose Empire, is kind of elusive right now. However, there are a few things we can put together to create a more complete picture. The first observation I would like to make is that the Forgery Shai makes for Ashravan does not interfere with the Resealing and vice versa. I find this most interesting since two or more Forgeries typically cannot be put on a person since they would interfere with each other. And given that this issue is never once brought up, I highly suspect that Resealing is a more permanent act than Soul Forgery- a stamp placed on a person couldn't just be undone by leaving the province or breaking the physical seal before. Resealing is also said to be very dangerous if not done correctly, and from such I believe that this system is more flexible in some ways than Soul Forging- at least when it comes to shaping one's body. Shai mentions that you must get everything down to a tee, since getting even a single blood vessel or muscle off in your stamp can kill the patient. Since this magic apparently isn't as locked into a safeguarded preset like Soul Forgery, I suspect you can directly alter the physical aspect (in theory) however you want. It's just such a complex and risky practice that doing much more than healing would be unlikely. One final observation I made was that Ashravan (though I think of overall less importance) would have presumably needed a Resealing very quickly, as he had a severe head injury that left him braindead. So, either you can do what Soul Forgers do and have many premade stamps (which, for the emperor is actually pretty likely) or it's a lot quicker for them to be made- perhaps instead of making an entire story of someone's alternate life history you just target an area of the body and carve a stamp that approximates what a healthy tissue in that area would look like and the magic does the rest. I had previously thought Resealing to be a mere training difference in its function than Soul Forging (and given Shai's commentary about choosing not to pursue it, perhaps it is a close enough cousin that MaiPon people could learn both), but given these differences I now believe it to be closely related by separate system that targets and modifies the Physical Aspect rather than targeting the Spiritual Aspect and being forced to adhere to its presets (though I'm sure Soul Forgery is the only of the two capable of affecting one's skills, memories, and Connections. Just worse at healing and probably reshaping a body). In other words, I think Soul Forgery writes an alternate story for a person or object that their Spiritweb aligns with, while Flesh Forgery directly takes the blueprints of their body and reshapes it as written by the Forger. With the advancements of Soul Forgery like universal stamps, it would be pretty cool to see Flesh Forgery gain applications for not just healing, but enhancing individuals (increasing muscle mass, bone density, reshaping organs to be safer from injury) or maybe for cosmetics.

All good points. Now, in this scenario if we're not doing 16 regular Misting doses, are we doing double that in raw power, maybe triple? Cause that also changes things a lot. I'm gonna have to update my list I think. I'd be half tempted just to make a 48x Pewterarm, but I suspect a lot of brute force will go to waste due to their limited mass (unless they're a Skimmer to begin with).

The tin being weaker is somewhat understandable since you could still technically get a little boost and see through the Mists, but copper's ability primarily is in countering Seekers and Cognitive manipulation- it should be overpowered with little difficulty unless you Invested a near-average amount, I'd think. Electrum is already kind of weak, only showing you up to a few seconds in the future. . . unless you just want to counter other future sight, I assume?

Fair enough. I will say though, unless Lerasium is way more efficient when creating a Mistborn than a Misting, it would probably be better to still give a Mistborn multiple alloys of Lerasium since you could given the most useful powers and double up on them but remove the less useful ones (enhance pewter, steel, and bendalloy, remove aluminum, cadmium, nicrosil for example). That said, a team of Allomancers can do things one individual cannot. Especially in a fight, having multiple members gives an enormous advantage over a single individual so long as they coordinate. Now, what I would say to make the challenge a little more locked into hard mode is if there was no Lerasium, only a Mistborn that was captured and had their powers stolen by sixteen separate spikes. Now you must use only one type of power per setup, you can only get up to four for any individual, and you must take into consideration Spiritweb damage on your agents.

I don't think it would change much for Hoid, assuming he'd be consciously willing to go anywhere near Nightblood. I think it's possible that Nightblood's Command could override Hoid's limitations on violence temporarily, but even then he tends to work from the shadows, as powerful forces in the Cosmere could obliterate him if he isn't careful. I think most likely they'd chat for a bit, Hoid gets bored from having a second highly Invested pal that can't be argued with, and then Hoid would find some excuse to dump it somewhere it wouldn't cause too much trouble (at least in his mind).

Ah, that's a really good point. One thing that comes to my mind in this situation is that you're way more likely to have loyal and trained individuals under your command as a government or other organizational entity (which I assume we are in this scenario) than Metalborn. Most agents you can readily pick from won't have the powers you want (or any at all). You want a Pewterarm/Steelrunner to give Lerasium to? The only one alive is an eight year old noble who hates [insert your organization here]. So I think it would be a spectrum. The less common their power(s), the more difficult it is to guarantee getting them and ensuring their loyalty and competency (excluding Investiture usage, which if they were born with naturally they have an advantage with). Mistings and Ferrings themselves are generally common enough that I think you could reasonably recruit and train one of whatever type you were looking for. Twinborn could as well, but since you can't cherry pick their innate powers they very likely won't have one that's perfectly ideal (though since we have a broader range of abilities we want anyway, it's probably doable with some effort and luck). True, fractional amounts of the enhancement metals would probably be more efficient since they work pretty well anyway.

This is really, really cool! I've been thinking about doing some homebrew stuff myself. I noticed that you incorporated a lot of the style that the Canon books provide- is there a platform that supports Cosmere RPG homebrew creation?

I find it difficult to imagine why we wouldn't remove some of the objectively less useful Lerasium powers from the bunch- after all, that's the strength of choosing to alloy the Lerasium with mundane metals. You get to cherry-pick the abilities you want and give them to who you want. If I were limited to 16 Misting-sized doses of Lerasium to create a crack team of Allomancers, this would be my choice: Tank/cannon (x2)- Pewter (x1.5), tin, steel, duralumin Support- Steel, tin, copper, bronze, bendalloy, zinc, electrum I would make two separate "tanks" that can both take a huge amount of punishment and dish out a lot of damage, working together. One and a half doses of Pewter means they can easily more than double their physical power, already putting them over the typical modern Pewterarm and letting them at least consider some other extremely tough Invested foes. Duralumin can be used strategically on top of that, especially when you mix steel in for massive Pushes. Tin is undeniably useful for stealth missions, especially in dark or hazy conditions. For the support I'd forgo pewter but keep steel and tin, as that's necessary to keep up with the tanks and to maintain proper clarity in dim conditions. Bendalloy can be used to crop up Speed Bubbles when needed, helping out the tanks. Copper is in a similar boat, shielding all of them from cursory Investiture detection and with practice might be used to help shield from mental-Investiture if their aluminum headgear went missing. Bronze is very useful, especially when dealing with sneaky magical beings or those with less understood powers (they wouldn't be able to tell what they do necessarily, but they could know to be extra wary). Zinc is useful for all manner of social situations, and can demoralize enemies. Electrum is the final power I'd give to support, since seeing the future, even in a limited way, is very useful. The support's main roll would be to act as a lookout, informant, director, and Slider for the team. Tanks have the obvious roll of heading in to cause damage. Definitely sad I couldn't fit in chromium, but I suppose they could rely on Allomantic grenades since that is one of the powers far easier to use through that method rather than natural methods.

Oh yeah, I'm the Shard's (self-appointed and completely unlicensed) Hemalurgy specialist. If it has to do with Spikes, Ruin, or Spiritweb manipulation, you can count on me to be watching from the sidelines. I would assume that they simply wouldn't have the knowledge to do so normally (assuming it is possible). I mean, what Nalthian would think to put their Breath in a metal spike- something that should require the 9th Heightening to truly Awaken- and then stab themselves with it? Not only is it unintuitive, but it actively goes against all common sense and instinct.

But, doesn't the quote from the world guide say only one pool functions as a Perpendicularity? Sorry, I don't think I'm quite following you.

While this did come to mind after the reading of Cultivations multiple pools, it just wasn't something I'd considered, probably because those are counted as multiple Perpendicularities but nobody ever mentioned there being more than one pool of Investiture for Cultivation.

So, I was reading through the Stormlight World Guide when I came upon this section for the Horneater peaks: "Deep within each of the Unkalaki oceans, a layer of regular water sits atop a hidden trove of liquid Investiture. Cultivation's Perpendicularity is in the ocean that the Unkalaki know as the Pool. Swimming all the way to the bottom of the Pool can transport someone to Shadesmar, which the Unkalaki consider the place of the gods." So, this means that while only the Pool holds a true Perpendicularity, each of the peaks has a pool of Investiture under their water? I had envisioned multiple heated lakes (probably cause by Investiture, but I had assumed it to be directly from the SR or something), sure, but not so much Investiture spread across them all. It's always fun to see how my biases are incorrect and I get a cool new piece lore to think about.

You are correct on Moahs- we have confirmation via WoB that his spikes are a form of Hemalurgy. The way I like to think of "Hemalurgy" is more like how I view Awakening now. I believe that Hemalurgy (the act of using a physical medium to staple pieces of Investiture to a living being, or potentially to steal pieces of Investiture from living beings) has general Cosmere-wide physics that can be exploited, of which I think that crystal spikes and Cinderhearts may be a part of. The term would be more overarching, with the OG Hemalurgy we typically think of being Ruin's special branch of the magic. The Father Machine was Awakened, but it did not use Bio-Chroma to achieve this. I think it is a reasonable enough assumption that if another Shard or person wielding power wanted to put Investiture into a spike and implant it into a host that it would be a form of Hemalurgy, but probably not be Connected to the Shard of Ruin (though given Nightblood's and the Nightmares of Komashi's black-colored Investiture despite their other Shardic origins, I think the act of stealing Investiture from a Spiritweb may be intrinsically tied to Ruin, though as with the Cinderhearts you could probably purify them afterwards). True, that is an excellent point. If they're holding a piece of Spiritweb already then they may count as a functional spike already, and the raw Investiture is just piggybacking off the bindpoint. That definitely points against my 3rd idea, as their could still be a viable Spiritweb fragment inside the Cinderhearts even after being purified of Ruin's Investiture (though I think there's still some wiggle room). Even with this being the case, you should still be able to staple raw Investiture to a Spiritweb, though you may need a small Spiritweb fragment to act as a bridge. Gemstones with Lesser Spren and then filled with Light, or spikes with Breath could probably still work as alternatives to Ruin's metallic spikes. A "true Spiritweb fragment" in my mind is a piece of Investiture that has been coded to function as part of a "living" organism, whether it be human, animal, Spren, or even Awakened construct. It cannot be free-floating Investiture that is just pulled in and used for fuel, such as Stormlight, Dor, or Mists. And also, yeah, I think Spiritweb modification will become more common as the Cosmere progresses, though with the rise of mechanical forms of Investiture the demand may not be as high as I once envisioned. Why bother becoming a Mistborn when a machine could do all the risky tasks you'd be able to accomplish and do so with far greater efficiency? There's definitely a personal factor to consider, but for the average person with the money and connections to do so, I think they'd go for the mechanical option, because it's easier, less permanent, and requires less personal effort. Another very good point. Yes, after further consideration with Rebeke's ability to remain Connected to the Cinderhearts, it was probably not Connection removal that freed Elegy from the Cinder King. Perhaps the removal of the Ruinous Investiture just kept her mind from being so vulnerable to the CK's influence, since she says "the voice" is gone from her mind after the Cinderheart's purification. Basically, I agree with your conclusion in large part, though I think their remaining Connection is probably not to Ruin but just to the other Cinderhearts and their Investiture. I think the Breath would still work in the Spike even if given to another, since Hemalurgy (at least Scadrial's brand) appears to bypass Identity to a degree. The reason I keep going back to the Breath-in-a-spike deal really is because it ties to a previous idea of mine: the main cost of giving Breath to another is that you must now live without it, and be at a notably lower quality of life. But, if you could put the Breath in a vessel that would allow you to continue benefitting from it while you lived but held onto it after you died, then it could theoretically be retrieved and given to those you will for it (though the system is obviously not foolproof and the spike could be stolen if not handled properly). To be fair, no true Sunheart has been attempted to be implanted into a person, the closest case being a Cinderheart that was purified during the process of being embedded into a host. So there is a real possibility that Ruinous power is still needed in some cases to make Hemalurgy viable, just not need to make it stick after the process is initiated. You know, Hemalurgy only needs to draw blood initially when grafted onto a person. Vin's earring does not need to touch blood after the initial spiking and can be removed and replaced as desired without injury. I wonder, is this a similar case to the purified Cinderheart? Could a bindpoint touched by Hemalurgy remain as a pathway for other Investiture to creep in even after the spike has been removed? My previous assessment of Spook's situation said no before on this idea, but as with Elegy having Ruinous Investiture removed doesn't necessarily mean that there isn't still some crack or Connection there, it just means at the least that there isn't the same weakness in the host as before. All in all, these are very good points you make. I enjoyed reading them.

Cinderhearts are kind of an interesting deal. They've been confirmed to use Hemalurgy in some way to work, appearing to be Hemalurgically Invested, then further Invested by Canticle's natural Investiture. They can then be pushed against a person, where they will bury into and consume the host's Identity, Connection, memories, and overall sense of self. Most interesting to me though, is that the extra bit of Hemalurgically aligned power can be removed, allowing a Charred to regain a small measure of self-control (which appears to have largely been done by severing the Connection to the Cinder King) and if done in the early stages of a Charred's transformation will still work as a Cinderheart but drastically change the extent of the transformation. For example, Rebeke's transformation into a Charred did not appear to damage her mind, personality, and did not burn away a large hole into her torso (at least not to the extent that the other Charred have had). She still appears to have full power from her Cinderheart though. To me, I think this hints at some things I'd previously thought about Hemalurgy and opens a few more ideas. This makes me think: 1. Hemalurgy doesn't require Ruinous Investiture to attach itself to a Spiritweb nor to continue its typical functions. If you could find some suitable Investiture and hold it in a vessel of some kind and use it to pierce the correct Bindpoint (such as Spren in gemstones, then implanted into one's eyes), I think the Investiture will do what Ruin's branch of Scadrian magic would do and allow access to that power. 2. Because the Cinderhearts did not suddenly become fatal after their Ruinous Investiture was removed, I believe that them becoming attached to the Spiritweb and reshaping the body to physically hold the vessel is not related to stealing the Investiture in the first place. In other words, I think that if you put some Breath into a spike and implanted it into the right Bindpoint (perhaps with added Intent, as it's possible this is the shortcut Hemalurgic Investiture plays after creating a spike through traditional means), the person could then access those Breaths. 3. The Cinderhearts appeared to mostly be powered by the raw Investiture found on Canticle and its sun. The amount of corrupting Investiture was very tiny, and did not appear to influence the overall power of a Charred once removed. I think that this half supports a long-standing theory of mine where Hemalurgy corrupts its stolen Investiture, but if Ruin's flavor is like what we see with Cinderhearts, it would be more likely to corrupt only a tiny portion of the stolen Spiritweb, but leave much or most of it the same as before. This also makes me think that raw Investiture captured in a suitable vessel for Hemalurgy could be used to staple onto someone without a true Spiritweb fragment. A purified Cinderheart, as far as I can tell, does this. So, Gemstones filled with Light, spikes filled with Breath, and perhaps other physical items could be used form Hemalurgy, no donors required (you likely would only get the basic effects of being Invested however, such as holding Stormlight or Breaths. Not true powers like Allomancy or bigger reshaping of the Spiritweb like with Koloss). Heck, I'd be willing to bet this is what nicrosil Hemalurgy tries to do, though it's limited to living donors most of the time given Scadrial's limited available Investiture. While I think these are all valid interpretations, I would like to leave a disclaimer that the systems found on Canticle and Scadrial, while similar in some ways, does not make them entirely parallel. It's very possible that more happens with Ruin's own evolution of Hemalurgy that would make these assumptions of mine invalid. Pending further evidence though, I think this is still a good place to look for what Hemalurgy in general could be like.

When Ishar claimed a portion of the Well of Control, it appears that he gained a status not unlike an Avatar. Wielding a small but very potent fraction of Odium's Investiture seems to have allowed him to do some crazy things, like Connecting himself into Shinovar to become its deity, supercharging his Honorbearers, and creating his own brand of human Fused. I wonder then, if he had enough authority as a conduit for Odium's power, could he have pulled away the Connection between Odium and the Fused, killing them permanently? On one hand, he is by far the lesser when compared to Rayse or Taravangian in Investiture, so a "tug of war" between their Intents would probably fizzle out. On the other, the power wasn't entirely aligned with its true Vessel (neither Rayse nor later Taravangian), preferring someone like BAM more. This doesn't necessarily mean Ishar is more aligned than the Vessel, but it does leave precedence for the Shard preventing its Vessel from forbidding another from using it in grand ways- and Ishar himself wasn't denied the use of Odium's power when he found the Well suggesting he may have been a decent fit for it, at least enough that he could wield it for millennia.

No, the Spren is where the power truly resides, the Radiant merely taps into that power via the Nahel bond. If you just spike the Radiant in an attempt to get the power the bond that's attached will let the Spren break it immediately, which should be just like with an Aviar bond that you steal since they use a mini-Nahel bond. I would also argue that Spren can use their Surges, albeit in a limited manner, since Syl has used Adhesion to prank people before. I think the reason they're so limited is the same as why Kelsier couldn't use Allomancy in the CR- no real ties to the PR make it much harder to weild Investiture.

You've read WaT, right?

Well, Hemalurgy is probably your best friend here. Just spike two individual powers from two separate Spren (and the bond from their Radiants). If that doesn't float your boat, convince two Spren of the right types to transform into Surgebinding Fabrials. Then use both to get the desired effects. Or, you could potentially create an Unsealed Metalmind granting those Surges, though you'd probably need to go on a few adventures and pull some favors from both Radiants and Feruchemists. If that fails, ask the Nightwatcher to give you those Surges, and if you don't like the curse you can theoretically spike it out later while keeping the boon(s). Might take some real experimentation first though, so be ready to live with that curse for a while. You might be able to become a Squire of two separate Radiants as well, which might also work. Depends on their willingness and how compatible Squires are with being mixed. Sounds like it's not what you're looking for, but it might be worth a shot.

In TLM, Gertruda and Dumad attempt to mimic and take the places of Wayne and Wax respectively, and at least Gertruda is going so far that she's trying to brute-force herself into enjoying pain because of a one-off situation where Wayne pretended to be crazy. I'm imagining that such a level of obsession in a person with Feruchemical gold might actually lead to them shape-shifting into a form more identical to that of the person they're trying to be. Not immediately, because that's a big cognitive change, and because gold isn't typically tapped for no apparent reason and when it is it is focused on repairing vital damage. But if Telsin and the doppelgangers lived I think Gertruda might eventually have stolen more than Wayne's hat. I suppose the real question of this post is then- what exactly could change a person's perception in such a way that they heal into a new body? Could it be as simple as some mental gymnastics and training, as Returned can do? Or, does it typically take an innate sense of self to be misaligned with how your body currently is, or could that sense of self organically evolve over time? Thoughts?

You know, if an Inquisitor ever shows up as a competitor option, I'd be all game to run that in a fight.

Same here. I've tried Googling specific topics to try and shortcut my way to reliable answers at times instead of searching the Arcanum directly, but Google AI also tries to answer the question itself. It draws on the many random ideas on the 17th Shard, Coppermind, and sometimes completely unrelated book series to confidently stitch together a totally incorrect Frankenstein of an answer. AI can be helpful in finding links to more reliable sources (though many go to incorrect places), but in my experience it's really, really bad at coming to an accurate conclusion, especially on vague sci-fi/fantasy stuff.

Now this is an interesting question. I'm going to assume when we say "most powerful" we mean which Shard can influence the Cosmere at large and outcompete other Shards in their influence. In this case, a few things come to mind. Raw power is roughly equal amongst them all, except for those that have permanent manifestations of their Investiture, such as Scadrial, Honor's Spren and Heralds, Odium's Fused and Unmade, etc.- though those are all drops in the bucket regardless. Intent matters much more, as it determines both what the Shard's ultimate agenda is and how its power can be used to achieve that agenda. A Vessel may disagree, but the Shard is the driving force in the relationship and will win in the long-term. Furthermore, the ability to kill other Shards is a very powerful ability amongst them. You can't rely on armies to fight other Shards, you must engage in combat between individuals. There are also so few other Shards that killing one immediately removes a huge obstacle to one's own influence. What's more, a Shard like Autonomy that pushes to have a large influence in the Cosmere but doesn't actually directly confront other Shards is actually hurting themselves I'm fairly certain, since now multiple other beings of equal cosmic power will seek their dissolution of power or straight up destruction, and I'm not certainly they'll be able to sidestep it indefinately. By these terms, Odium ranks very high, at least when in combination with its historic Vessels like Rayse and probably Taravangian. It's A-Okay with murdering other powers, has been seen holding massive influence despite being directly opposed by two Shards and their own powers, and it is going to be alright with its Vessel using dirty tactics. Ambition would almost certainly been a candidate for "strongest" under the definition I've set, but Odium/Rayse managed to oust it before it got to scheme for terribly long. Ruin would, I think, have some real potential to do damage- it's primary magic system appears to be parasitic in nature and can override other Shard's influence, and I kinda think the Shard itself may have an easy time with that type of ability. It's also a lot less stable though, as it mostly just wants destruction. That's not a good long-term, sustainable method of getting more of what they want though (more destruction), since it draws other Shards into conflicts of interest and Ruin often hurts its own minions and allies. Plus, it has difficulty with future sight. So it's probably harder to justify as one of the truly more "powerful". Cultivation has been seen having good future sight, and it wants progression and growth. That's pretty good, and I think could be wielded similar to Ambition's Intent in the right Vessel, pushing the power to continue expanding its influence and eliminating factors that stand in the way of such growth. Realistically, at the end of the day a Shard's real power depends on its Vessel. How it is filtered and used probably depends more than everything else. But its Intent can be a huge factor as well, and some Intents are simply more stable and open more options than others. So I'm going to say that either Ambition or Cultivation have the most potential for power, at least from the ones we've seen thus far (Invention hasn't been witnessed enough to really tell, so I'm not even going to touch that).

I would like to point out that we do not have confirmation that the spikes used by the Set are made of nicrosil. I think it's the most likely option, but it could very well be that they tried to use the typical metals for extracting powers because that's what they knew already worked. I do think that they were probably nicrosil. I just felt the need to point out that it isn't technically canon yet. Sounds like a solid idea. My personal take on the matter of why the Set's experimental spikes didn't quite work is twofold: First, as you said, Identity contamination. Having so many conflicting soul fragments in one bindpoint is probably going to confuse the Spiritweb so thoroughly that it's a miracle anything useful would attach to the bearer. I think the reason their was some measure of success was probably because a random piece of Spiritweb temporarily aligned with that already existing in the bearer- i.e. if they had the buried potential to be a Coinshot and a Spiritweb fragment that belonged to a donor that also had the potential (and a higher than average one at that) to be a Coinshot, then they could stack and make the bearer of the spike become a Coinshot until hypothetical fulgurations in the spike caused them to misalign again. Second assumes that the Set was in fact using nicrosil as their Hemalurgic focus for these experimental spikes. From a meta perspective it would be very weird for nicrosil to be capable of achieving the same results as all other power-grafting metals. That's what refined Atium does! It would be awfully weird to give one of the (as I understand it) cheaper metals the very power of Ruin's essence (perhaps less efficiently, but still just as versatile and way, way less expensive). I'm going to make the leap of logic that nicrosil Hemalurgy can steal more or less any innate Investiture on a Spiritweb, or at least the extra not directly related to a creatures innate attributes, but it does not preserve the original function as well as most spikes. Over time, their contents could decay into a more base form of Investiture, one that isn't coded to provide a specific power as with other spikes, but instead would be like grafting on Breaths or other innate Investitures from different worlds. That would also fit well with this WoB stating that nicrosil is used to steal general Investiture, not powers. This could help explain why there were some results in the experimental spikes creating powers, but only temporarily. The spikes could have broken them down into a less usable form over time, as that's not what they're designed to do.

That is an excellent question. The Metallic Arts are more ridged in what they can do than Stormlight or Breaths- it's as if they have a kind of program encoded into them as they are drawn from the SR or a Spiritweb. Allomancy, for example, would require some extra fiddling to be fueled by Stormlight, and I find it likely that the reverse would be true. Feruchemy is likely in the same boat. I think that blanking Identity would technically make it easier for the Spren/Radiant to access that Investiture since it is no longer locked to the Feruchemist who made it, but Unkeying a Metalmind is not the only step that must be taken to utilize the Investiture within. Unsealing would be necessary, as you not only need the Investiture to fuel the process, but you need to be a Feruchemist to tap it (which the nicrosil portion does in an Unsealed Metalmind. However we do not have any confirmation that an Unkeyed Nicrosilmind equals an Unsealed Metalmind, if that makes any sense). To recap my thoughts on this, I don't think that a Radiant or their Spren could access the Investiture within an Identity-blanked Nicrosilmind in the same way they can consume Stormlight. Stormlight has no known "code" hard written into it and (presumably) neither Radiant nor Spren are Feruchemists, nor do they even have a smaller Connection to the Shards that created the system of Feruchemy (looking at Venli using Voidlight to fuel her Radiant Surgebinding, it seems that a lesser but still strong Connection to a Shard that does not provide the power they're using can then allow uncoded forms of Investiture from the second Shard to be used as a fuel source. Put more simply, if you get a sufficient Connection to another, non-native Shard, you should be able to use their purer form of Investiture to power your parent Shard's abilities for yourself). The Radiant should be able to use an Unsealed Metalmind for its intended purpose though, and I believe that the Spren themselves might even be able to.

I don't think the metals on their own would change how the Shardblade manifests. Thinking on it further, Allomantic/Feruchemical metals do have an impact on Spren in gemstones though, so I think you could create a device that would use the Blade's Spren to manifest some new effect. It may take some work, likely more than just physically touching the metal to the Blade, but I don't think it would be terribly hard once people thought of it.