Weltall

Brandon has been asked this and his response was that a spren could manifest as multiple objects in the Physical Realm but this would require splitting their soul and 'they wouldn't like that very much'. So it's not something we're likely to see happen.

Whatever method is used to create the Bands and the medallions (and we don't know what it is yet but The Lost Metal is going to go into this) grants the ability to use the various Allomantic and/or Feruchemical powers associated with them. Oh, and to split hairs, the Bands were believed to be Rashek's bracers but in actuallity they were created by someone else entirely. Take a look at the very last scene again...

I'm not certain that Roshar's extremely unusual geology allows for the existence of elemental aluminum that could be harvested. The primary source for aluminum is in volcanic deposits (a point that's mentioned in connection with the source of aluminum in the Mistborn series so Brandon's done the research here) and since Roshar doesn't have plate tectonics it doesn't have the mechanism that produces volcanoes on 'normal' planets, hence no good source for elemental aluminum. The process we use to refine aluminum in bulk requires a level of technology that Roshar hasn't reached yet so it's extremely unlikely that they discovered the metal that way in the distant past. 'Honor/The Heralds/Other Worldhoppers Did It' makes more sense in this context, methinks.

Right, just pointing out that Elantrians seem to be a very special case. For something like ChayShan, I'm pretty sure that you'd need a hack of the system to make their powers work offworld. They wouldn't necessarily be able to fuel their system with Stormlight. (Spoiler for Words of Radiance) I think that ChayShan would probably work the same way, where the magic system specifically needs 'Dor-flavored' Investiture to work rather than any available Investiture. It's quite likely you could make ChayShan work somehow but it might be more complicated than just gaining the ability to inhale Stormlight. Thougn admittedly, a spren bond with the attendant alteration to your sDNA might be the sort of thing that helps make such hacks possible, if you have the sDNA for multiple systems it might be easier to figure out how to get aspects of one magic to work within the framework of another.

Taln's spiel talks about Soulcasting bronze to make weapons with the implication that this is his standard message to the peoples of Roshar whenever the Heralds return. If Kalak knows how to do that, he could easily have learned aluminium at some point and passed it on shortly before Aharietiam, and the millenia without a Desolation allowed that knowledge to remain instead of being lost. If the Heralds didn't come from Roshar originally but were from, say, Ashyn before a mass-migration to Roshar that got remembered as the Tranquiline Halls>Roshar exodus, maybe they knew about aluminum from that planet. What little we know of Ashyn suggests it's the kind of place where aluminum could be found naturally. Or Tanavast taught the secret of the metal to them. Either way, very good question!

Not necessarily. Brandon has said that an Elantrian could travel offworld and would still be an Elantrian, though the obvious visual signs would vanish. Evidence, a certain worldhopper. I think the Secret History example isn't Elantrians needing to 'top up' on the Dor generally so much as it is something specific to their circumstances.

I think it was nothing more than Raeth being the first potential host that Makkal has ever come across. The thinking goes sort of like this, as I imagine it on Makkal's part: 'Here's a person who's bonded to one of 'my' Aethers who I can touch through the perpendicularity (or whatever we want to think of the pools) and who didn't fall completely through it. And he's not touched by Agaris' influence.' Remember that the Patriarch mentions how all the Dari that are picked to bond Night have been visited by 'Vae'? I think that they could bond Night and create the Forgotten but since they were first touched by Agaris, they couldn't be used as a vessel by Makkal. Not that I disagree that the ending could be greatly improved, and like I said I think that when it's rewritten we'll get something a lot more satisfying since Brandon will be envisioning it as a standalone project instead of the springboard to a longer series. We're told that Aethers weaken if they're not used (the Patriarch) so we know that the strength of the bud you recieve isn't fixed as your power level for your entire life. My working assumption is that Raeth for some reason simply wasn't compatable with the Amberite bud or got some quirk of sDNA that made him less suitable to use his world's magic system and so he required a direct infusion of power from Makkal to allow him do do the kind of impressive stunts that other Amberites could easily accomplish. And consequently, the bud that D'Naa took from Raeth was useless rather than ridiculously powerful because it had decayed from its strength when he'd recieved it.

Yeah, Inquisitor spikes aren't as 'personal' as kandra ones (they're a special case because theirs also fixes the cognitive block they have as mistwraiths) so if he couldn't recover his original spike he could have grabbed an appropriate one from the corpse of an Inquisitor.

I think that's pretty comprehensive. Brandon hasn't mentioned Skyward in quite a while that I'm aware of so I'm not sure if that's going to be A Thing still or not. And if you want to discuss the potential Shardic implications of Aether of Night's eventual rewrite, there's a good topic on the AoN discussion board going over our ideas for how we'd 'fix' the issues Brandon has mentioned with Aether and/or how we'd integrate it with the rest of the Cosmere. But my own guess is that we'll get another Shard out of it when the time comes. Oh, and while it could be refering to Autonomy (per the theory that Bavadin isn't located on Taldain but rather its sun) we have WoB that there is a Shard that isn't on any planet.

The Arcanum Unbounded essay talks about Sel having multiple continents so it's a good bet that the mysterious 'third great domain' is based on a different landmass that we haven't seen yet. And with at least two more books to be written we'll undoubtedly learn more in the (relatively) near future, but for now all we know is that there's another major power somewhere on the planet.

Yeah, Apocalypse Guard isn't technically the same universe as Reckoners but it is part of the same multiverse and Brandon mentioned back when he announced it that one of the things it would do is explore the Reckoners mythology in more depth so the odds are good that we'll learn more about Calamity's origins over the course of the trilogy.

Welcome to the Shard! We're at about the time when atium should start reappearing, per Kelsier's guess that he ended the creation of new geodes for about three hundred years. And atium is referred to as the Lost Metal in-universe, which just so happens to be the title of the final book in the era. There's some question over whether atium and lerasium can be produced the way they were during Era 1 now that Preservation and Ruin have been merged into Harmony (who's got his own godmetal) but either way, there's been enough talk of potential alloys of the godmetals that we almost have to see more atium and lerasium eventually. And if the old Word of Peter is still valid, there's at least one unaccounted-for lerasium bead floating around...

Not to mention the Set. The God Beyond seems more like a concept that's spreading across the cosmere rather than a religion per se so I doubt it would count as one of the four.

Well why do you think he was so keen on ruining Scadrial before it could get to that point?

Yeah, the Eras all line up with what Brandon has been telling us ever since he settled on that system instead of the older division by trilogies, with Wax and Wayne being a sort of weird outlier. The '2.5' one was mentioned in the 2014 State of the Sanderson as a 'maybe' project and he's also said that he might do some 'near future' works set between Eras 3 and 4 (here). Also, I corrected my goof where I mistyped Era 2 when I meant Era 3 as the ones that can't come out until the Elantris sequels are finished " because of behind-the-scenes Cosmere bits" to use Brandon's exact words.

The cosmere's timeline makes pinning down 'who's the most advanced' a tricky proposition since we only know of a couple stories that happen close enough together to make a direct comparison, Stormlight Archive and Era 2 Mistborn, with Warbreaker happening somewhere close as well. Taldain is the first world we've seen chronologically to develop gunpowder but we don't know how they've developed since White Sand, as Autonomy has interdicted the planet. It doesn't mean that progress has been stagnant (it seems more like Autonomy wants to keep outsiders from influencing the planet's development, than stopping it entirely) but it does mean we don't have a good idea what's been going on there for a long span of time. We have a WoB that they are the most developed planet despite this interdiction so they've apparently continued, just without any outside influences. Thanks to @Pagerunner for the Reddit WoB list (link) For Scadrial we have Khriss' observation in Arcanum Unbounded (written at some point prior to the events of Sixth of the Dusk) that were it not for Rashek's thousand year interference, Scadrial would probably have surpassed every other world in the cosmere in development, Silverlight included. That's a pretty impressive statement. And we have WoB that they're continuing to develop at a relatively fast pace because the world has been and still is relatively safe for worldhoppers, there are cosmere-aware individuals pushing for development behind the scenes (like the Set) and Harmony is actively interested in the technological progress of the world. Certainly they're the most advanced world whose progress we can quantify. Elantris had very advanced applications of AonDor before the Reod but we don't know what their development looks like closer to the 'present' era of Mistborn 2/Stormlight, or Sel as a whole (and there's at least one major power on the planet we know nothing about). We'll probably find out soon though as Brandon has indicated that the Elantris sequels need to come out before we can get Era 3 Mistborn.

Best one I can find:

@Con578 Well spotted on Vasher. If you're looking for potential worldhoppers from other stories in Stormlight Archive, I'd also suggest you keep an eye out for anyone who shows an interest in Hoid and look for margin comments in the illustrations. There's a few confirmed worldhoppers who aren't going around advertising themselves by name. And then there's Felt who actually is using the same name but he's very easy to overlook, And we know at least one Ghostblood was born offworld, though they aren't a returning character from another setting like Zahel is. We have quite a few of them. Here's a small sampling.

Hoid also refers to Kelsier as 'friend' in Secret History, just before he (cognitively) beats him bloody. And while he recognizes Kelsier, the reverse is most certainly not true at this point in time. And he calls Kaladin 'my young friend' the first time they meet in Way of Kings. Calling people he doesn't intimately know 'friend' is well within Hoid's character so we shouldn't read too much into what he says to Taln.

Yeah, Rashek's plan was 'create a stable empire that will last long enough for the Well of Ascension to refill, rinse and repeat' and selectively supressing technology helped him in that goal by making it harder for anyone to challenge him. We're told they had gunpowder beforehand and the logic of supressing it is obvious: Guns don't require as much training to be spectacularly lethal as bows do (making it easier for a rebellion to mount a serious threat) and bullets are harder to deflect with Allomancy than arrows (increasing the risk to Rashek, if only slightly) so that just had to go. And they also had steam technology and were getting close to an era of locomotives. Making long-distance travel harder (which naturally affects communication as well) worked to Rashek's benefit also. However, he also encouraged useful technologies that didn't pose any threat to his reign like pocketwatches and of course his backup plan in the event that Plan A failed required canning technology to create the survival caches so he ensured that developed in time for the next cycle.

Other way, Khriss says that Initiation on Elantris is different from, for example, Vax. So we can neither confirm nor deny the possibility that Vax is a new name for Vaeria based on that and Brandon has RAFO'd any questions on the subject. I've also seen speculation that Vax could be the setting for Dark One, which is going to be part of the cosmere whenever Brandon writes it. Based mostly (I imagine) on the fact that it's the only other unpublished cosmere work we know about whose setting isn't already known to us. Well, unless you count Skyward but I don't think Brandon has said anything on that one for a long while, while he does keep bringing up Dark One.

@Calderis That's the one we're reasonably certain of. And yes, yes it is. xD

To add, while it's not canon and whatever is written in it shouldn't be presumed true for purposes of discussion in other boards, Brandon has told us that he plans to rewrite it eventually. We don't know much more than that at this point but when it does happen, the rewritten work will be canon. And he and Peter have both indicated that there are references plural to Aether of Night in published works, as he's always intended to have the Aethers in the cosmere in some form. We're pretty certain what one of the references is, another is subject to debate. Enjoy the read!

Maybe not in terms of Savantism but something like this might be possible. We have a Word of Brandon that burning a hemalurgic spike would splice your sDNA and that contained within the spike with 'very strange consequences'. So we don't know exactly what it would do but the result could be a permanent transfer of some of the sDNA to you. But he did mention strange consequences so it's probably not as neat and tidy as that and you'd have to be stark raving bonkers to test it out. Wax is/was planned to be an Allomantic savant with his steel, Brandon talks about it here, though like you said the way being a savant works is somewhat up in the air right now. @Calderis has mentioned why an ordinary Feruchemist probably isn't ever going to become a savant; not enough Investiture messing around with your spiritweb in the way that Allomancy or fabrial-based Soulcasting does.

Yeah, Lightweaver Death Ray was mentioned by Brandon as 'possible but so inefficient that it's not happening' along with other possible Investiture tricks like using Forgery to make a Shardblade. But some sort of fabrial making use of Gravitation (either as a quasi-railgun or more exotically for long-range Lashings) seems entirely possible for Rosharans to develop given enough time. Though my guess is that we wouldn't see something like that until the end of the series, or post-SA in the big cosmere crossover that Mistborn Era 4 is supposed to be.