Given the similarity between the words "Adonalsium" and "Adonai," the prevailing idea is that the fragmented entity is something like God. However, in one of the Cosmere books, the word "Adonalsium" is (IIRC) mentioned near a discussion of how some seemingly gibberish words are mistranscriptions of real words, or some such thing. Consider, then
- Adam-ondi-Ahman
In another Cosmere book, we are told that of the three metal-based magics in the relevant world, it is Hemalurgy that is most relevant to the entire Cosmere (or something along that line), which I thought was weird because Hemalurgy is the magic used mostly by the forces of evil in that story. It's based on pounding metal spikes through people's bodies, to transfer various powers from body to body and the like. But then the citadel of the Lord Ruler, the pseudo-God from the first Mistborn book, is also said to resemble a host of Hemalurgic spikes.
In The Way of Kings, a character tries to prove that God exists used an argument-from-appearance-of-intelligent-design related to the layouts of various cities. Cities are the main type of setting Sanderson has used across the board in his fantasy stories (Elantris, Hallandren, Luthadel, etc.).
Judeo-Christian/Mormon theology involves plentiful references to a Zion and a New Jerusalem, a great and eternal city that will be constructed from various crystals (twelve, the Book of Revelation says) at the end of time.
So... drumroll...
What if Adonalsium was a living city?