Nicosium

Thanks for the heads up! Seems like I ought to do more research next time and I'll try to find and honor those who were before me

Disclaimer: I have no idea where to put this, so please benevolent mods, move this if necessary. SPOILER WARNING: Alright so, this theory contains the heaviest spoilers in the world for Stormlight Archive Rhythm of War, Warbreaker, Elantris, Tress of the Emerald Sea, and I might have to borrow from Mistborn Era 2 It also spoilers ALL of Avatar the last airbender and Legend of Korra. The world of Avatar almost perfectly fits into the cosmere, here me out. I'll be using cosmere words like Bond, Connection, Investiture, Spren, Shards, cognitive realm, Intent, and the like, so if you don't know any of those, read the cosmere books before reading on in this theory. I'll to capitalize those words in order to make them stand out. I will call the Avatar-World the Avatar-World in order to avoid confusion. --- Let's get started, first of all, of course there are not really fitting shards left over for this planet, but to put it simply, something similar to Roshar is going on. Spren-like splinters called Spirits inhabit the Cognitive Realm known as the Spirit-world of the planet Avatar-World, and two perpendicularities known as Spirit Portals in the North and South pole of the planet exist. This is a fact that points towards two Shards of Adonalsium having been shattered on that world. The Spirit World, Spirits, and the Perpendicularities Judging from the original humans having been in the Cognitive Realm first, they might've migrated over from another planet, before having been changed by Cosmereological Intent (see Pure Lakers on Roshar) to let the ever present but Mist-like (see Scadrial) invisible form of Investiture known as Chi, flow through their bodies. The Spren/spirits/splinters of those Shards known as the lion turtles could thus grant the humans a special form of Bond to allow them to use the power of an element. In the Avatar-World there must be two new types of Bonds: one that lion turtles use to grant the ability to use investiture to control and element, and one bond that Spirits use to possess a human. Bending and Investiture - an End-Positive System Forming a Connection to the power of the Splintered shards (see what happened on Sel), this Bond is not very similar to the Nahel Bond (Roshar & Spren) and a Luhel Bond (Lumar), but instead only requires an initial bond that unlcoks the power in a human and can then be passed on genetically. Investiture in the Avater-World in the physical realm is an invisible gas, or at least humans have evolved to not see it, and is ever-present, seeping into the humans where it is called Chi. The unlocking of bending and chi-gates might form cracks in the soul that are passed on genetically, seemingly even the more powerful Splinters or rather Cognitive Shadows can hold such powers, as evident by Raava and Vaatu. Bending itself is a way of Accessing Investiture, requiring intent and specific physical movements that look almost like a martial art. This is similar to Aons drawn by Elantrians using AonDor or the martial arts on Sel. The Avatar Both bonds were used by Raava and Wan to create the first avatar: A cognitive shadow that holds memories of all prior avatars, held together within a human body by the Spirit Raava. Whenever an Avatar dies, the memories are added to the cognitive shadow known as the Avatar, and the spirit Raava carries it on to a newborn human from another nation to use the possession Bond with. Similar to a Bondsmith, the Avatar can create and sever connection, such as completely taking someone's ability to bend, or temporarily elsecalling into the Spirit World (Cognitive Realm). Chi-Blocking Chi-blocking blocks spiritual pathways for the Soul which investiture would need to take. Healing Healing works well in the Avatar-World since due to the physical movements through which investiture is accessed, the humans of the Avatar-World have developed a stronger image of self and their cultures, even associating them directly with how they can use investiture. Savantism Savantism in bending might require something more than just a lot of investiture and using their power, but these are known as specialized bending types. --- Tell me what you think. Did I make any mistakes? Any way you can fix my mistakes and still make it fit?

On this note, pure Tanavastium and pure Korraveliumium can likely be used as metalminds. Shardblades and the like (mixtures of Honor and Cultivation's investiture) are unlikely to be viable Allomantically or Feruchemically, due to not being true allomantic alloy pairs (that would likely be Godmetal + "Normal" Metals) Though, Lerasium already seems like an example that would allow shardblades to be burnt, as it behaves strangely with other metals What would interest me personally would be what a Tanavastium and Lerasium alloy would do if burnt.... Would it create a sort of Surgebinding Mistborn? Or not do anything?

Sounds like you should be a narrator so you can actually learn something from this list. Edit: Meant purely comedic of course, although from the no-no-list, it seems like you'd actually make a fun narrator

I've been thinking about this a long while since I am currently running a Mistborn Adventure Game campaign and want to include a higher spren. Personally, I suspect there might be some way to get Spren/Cognitive Entities keyed to a shardworld (/and by extension Shardblades and stuff) off world by one of the following ways: I always thought using Aluminum, plus regular intake of (Secret History Spoiler) Dunno if this would work, probably not? Though I am not quite sure how to get the spren into this equation, Feruchemy could be used to (Bands of Mourning spoiler) (The Emperor's new Soul spoiler) I don't know how exactly these could be

I think the whole "not-being-able-to-have-children" thing is a big part of the religious doctrine. It is one of the preachings the gods are told about the very nature of their being, like the titles they are given, and the resulting selfimage. Like Vasher's control about his appearance and thus drab-nature Rythm of War Spoiler would suggest, I think the main reason they can't have children is because they think they can't, a sort of variation of intent they assign themselves to their "sort-of Cognitive Shadow" nature. They think they can't have children because that's what everyone tells them, so their souls reflect that belief.