Lemons

That's a solid point, I think I might have misremembered a WoB when I placed those two as opposites, looking at the ones I can find suggest you're right in them not being. Odium could easily sit in Whimsey's slot, and Whimsey would sit as a structural opposite to Honor (this is one of the issues with the categories being so speculatively named at this point, often several combinations could fit a single shard). Honestly Brandon has stated that not all shards have strong opposites - I was thinking this could be the origin of the 16 shards and the symmetry we see in them. Exact behaviour of any shard and it's investiture is going to be very much down to emergent intent, vessel, and as mentioned, rule of cool! Any thoughts on the if the overall structure and it's origin holds up even if specific shards are debatable?

TL;DR I propose that the 16 Shards of Adonalsium can each be uniquely described by four independent binary axes — two from the Dawnshards, two from the four aspects of Adonalsium: Change / Exist (Dawnshard) Focus / Connect (Dawnshard) Intellect / Emotion (Adonalsium aspect) Impersonal / Personal (Adonalsium aspect) Every Shard has exactly one structural complement — all four values flipped — which naturally produces the confirmed opposing pairs (Ruin/Preservation, Honor/Odium, Devotion/Dominion) and predicts five more. All sixteen Shards are placed with reasoning given for each. Six placements are anchored by confirmed lore; ten are derived and open to challenge. Dragonsteel will presumably settle it. Overview The idea of using binary yes/no axes to categorise the Shards rather than simple groups of four has been touched on before by multiple people both here and elsewhere on the Internet. These typically propose that the Dawnshards operated in a primary/secondary hierarchy to produce sixteen Shards from four. What I want to propose here is a more systematic version of that approach, with a key structural difference. Those models attribute the full structure to Dawnshard action alone. This leaves an unresolved problem: Shards that share the same Dawnshard signature feel radically different from each other. Ruin and Cultivation would be in the same group; so would Honor and Preservation. A Dawnshard-only model has no mechanism for explaining that variation. I propose that Adonalsium's own four aspects contribute an independent second axis. The result reflects both what Adonalsium was and how it was cut — neither alone is sufficient. This means we should be considering the 16 shards as a result of a 2⁴ split rather than 4² — the structure is nested binary pairs all the way down, not a simple grid. It is common in psychology and philosophy to describe personality or character using graphs with two independent axes of opposing characteristics — for example introvert/extrovert vs thinking/feeling. I propose the four aspects of Adonalsium work exactly this way: Emotional vs Rational — whether a Shard's fundamental nature operates through feeling or intellect Personal vs Impersonal — whether a Shard's power is directed toward specific individuals and relationships, or operates universally without regard for particulars. This distinction often manifests in magic systems as internal vs external I propose the Dawnshards have the same opposing pair symmetry: Change vs Exist — the most fundamental opposition, between transformation and continuity. Change Shards reshape reality; Exist Shards maintain and persist within it Focus vs Connect — the perpendicular axis. Focus is self-referential power: intensifying, amplifying, bringing something to its fullest expression independently. Connect is relational power: reaching outward, forming bonds, operating through networks and relationships between things. A fire burning brighter vs a fire spreading. These two are pure speculation based on summetry observations while experimenting with this theory. Combining two pairs of two gives 2⁴ = 16 unique combinations — exactly one per Shard. The Address System Each Shard can be described by its unique position on these four axes — one value from each pair. Rather than writing out all four values every time, we can express this as a four-digit shorthand, where 0 represents the first option and 1 the second in each pair. We'll call this the Shard's address. So a Shard that is Change/Focus/Intellect/Impersonal becomes 0000, while Exist/Connect/Emotion/Personal becomes 1111. The four bits are: B1: Change(0) / Exist(1) B2: Focus(0) / Connect(1) B3: Intellect(0) / Emotion(1) B4: Impersonal(0) / Personal(1) Every Shard has exactly one structural complement — all four bits flipped. This produces eight complementary pairs. It is worth noting that Sanderson has confirmed not all Shards have a directly paired opposite intent in the way Ruin and Preservation do. This is consistent with our framework: we used Shards with diametrically opposed intents to anchor the logic, and it stands to reason these would have opposite binary addresses. However, not all opposite-address combinations would be expected to produce the same antagonism. Two Shards maximally different in structural composition may simply have nothing to say to each other rather than actively pulling against each other — particularly where one combination of axes leads toward apathy or disconnection rather than active opposition. Devotion and Dominion are a particularly instructive example. They are confirmed structural complements — maximally different addresses — yet on Sel they cohabited rather than clashing. This is because their intents are not inherently antagonistic: you can be devoted to an empire. Love and control can be deeply complementary rather than opposed. A devoted subject and a dominating ruler need each other. Compare this to Ruin and Preservation, whose relationship was defined by active tension — Sazed finding Harmony genuinely difficult to wield precisely because those intents pull against each other. Notably, even in death Devotion and Dominion's investiture cooperates as the Dor rather than fighting, which is exactly what we would predict from a non-antagonistic structural complement pair. Methodology We anchored the system using three confirmed opposing pairs from the text: Ruin / Preservation Honor / Odium Devotion / Dominion We assigned addresses to our three anchor pairs by reasoning from their confirmed Intents: Dominion(0000): Change/Focus/Intellect/Impersonal — impersonal control imposed through systems and force. Skaze seeking political dominion without personal investment in specific outcomes. Ruin(0001): Change/Focus/Intellect/Personal — Ati's corruption was deeply personal. Ruin whispered to specific individuals, manipulated specific people. Entropy with a personal touch. Odium(0010): Change/Focus/Emotion/Impersonal — impersonal passionate transformation through intensification. Honor(1101): Exist/Connect/Intellect/Personal — oaths are fundamentally intellectual constructs between specific individuals. Preservation(1110): Exist/Connect/Emotion/Impersonal — Leras maintaining everything equally, the mists preserving all of humanity without distinction, investiture distributed universally. Warm but undirected. Devotion(1111): Exist/Connect/Emotion/Personal — directed love toward specific things is fundamentally personal. Seons bonded to specific individuals, love that persists and connects. Proposed Shardic Alignments Shard Address B1 C/E B2 F/C B3 I/Em B4 Im/P Confidence Dominion 0000 Change Focus Intellect Impersonal high Ruin 0001 Change Focus Intellect Personal high Odium 0010 Change Focus Emotion Impersonal high Virtuosity 0011 Change Focus Emotion Personal high Invention 0100 Change Connect Intellect Impersonal medium Cultivation 0101 Change Connect Intellect Personal medium Mercy 0110 Change Connect Emotion Impersonal low Endowment 0111 Change Connect Emotion Personal medium Autonomy 1000 Exist Focus Intellect Impersonal medium Ambition 1001 Exist Focus Intellect Personal low Whimsy 1010 Exist Focus Emotion Impersonal low Valor 1011 Exist Focus Emotion Personal low Reason 1100 Exist Connect Intellect Impersonal medium Honor 1101 Exist Connect Intellect Personal high Preservation 1110 Exist Connect Emotion Impersonal high Devotion 1111 Exist Connect Emotion Personal high Structural Complements Dominion / Devotion Confirmed opposing but not high friction Ruin / Preservation Confirmed maximally opposing Odium / Honor Confirmed opposing intents Virtuosity / Reason Structural complements — derived, but common to oppose art and reason Invention / Valor Structural complements — derived Cultivation / Whimsy Structural complements — not necessarily antagonistic Mercy / Ambition Structural complements — supported by Threnodite battle Endowment / Autonomy Structural complements — derived Notes on individual Shards Autonomy — does not promote individual autonomy. Operates through cold hierarchical structures, proxies and isolation. The Shard is autonomous rather than, in general, promoting autonomy in others. Mercy — passive compassion would place Mercy in Exist. But active intervention — stopping the Ambition/Odium conflict — places it in Change. Whimsy — almost certainly a reductive translation. Possibly closer to Wonder, Emergence, or Spontaneity — the capacity for reality to produce the unexpected. Odium — claimed by Rayse to actually be Passion rather than Hatred. The name is a hostile translation of something more like undirected intense emotion. Interesting Implications Rayse vs Odium — Rayse's targeting of Ambition was likely personal rather than structural. Odium's true structural opposite is Honor. The Ambition fight being so costly makes sense — Rayse was fighting from personal motivation rather than structural advantage. Mercy/Ambition at Threnodite — not coincidence. Opposing pairs being drawn to the same conflicts may be a structural feature of the system. The Dor — Devotion and Dominion's combined power being a polarised storm is exactly what you'd expect from two maximally different Shards' investiture forced together. Reason hiding — perfectly consistent with Exist/Connect/Intellect/Impersonal. A Shard that simply persists without acting. Cultivation's plan failing — a Change/Connect/Intellect/Personal Shard playing a long personal game against a Change/Focus/Emotion/Impersonal opponent. Odium operates on completely different axes, making Cultivation's miscalculation structurally legible. Whimsy declining to help Roshar — Harmony described the response as troubled rather than simply unhelpful. If Whimsy is Exist/Focus/Emotion/Impersonal — spontaneous, undirected, fundamentally not oriented toward personal intervention — then helping would require directed action toward a specific outcome, which is structurally contrary to Whimsy's nature. A Shard of pure impersonal spontaneous emotion has no investment in outcomes; good and bad are equally surprising, equally interesting. Harmony would find it troubling that Whimsy didn't decline out of indifference but out of something closer to detached amusement — finding the entire Cosmere conflict genuinely entertaining rather than alarming. Caveats The four axis names are working shorthands, not claimed to be Sanderson's actual terminology, particularly the focus/connection axis - finding a good descriptive linguistic pairing is hard for this concept. Some shard names are taken to be deliberately misleading - which fits what we see with their actions for some shards like Autonomy. Six strong placements, five reasoned placements and five from names alone. The system predicts specific things that could be falsified. Dragonsteel will presumably either validate or demolish this entirely! Conclusion I feel like looking at it as a dawnshard split and an adolnasium split has some interesting structures that would help explain the symmetries and oppositions that we see. Exactly placements and splits are a first attempt - but I'd be very interested what everyone thinks of the overall theory. Thanks for reading!