I think that Brandon really loves creating logical patterns like the way every metal has its opposite and,in the same way, all shards (known and unknown) will complete each other in pairs So then you have (those bolded are the ones we know): Ruin / Preservation
Odium / Affection or maybe Honor
Honor / Trickery or maybe Odium
Cultivation / Famine or maybe a Modern Consumerist Culture God
Endowment / the God of DEPT Devotion / Apathy Dominion / Freedom
And then we have 2 missing shards. OFF TOPIC THEORY: I think that if Brandon is the ultra writing machine that we think he is, then maybe once two shards are combined, they will also form other opposing or complementary shards (ex: Harmony formed out of Ruin and Preservation - complements Discord possibly being formed out of Honor and Odium)
And maybe then they will keep on combining until we have one last conflict between 2 major shards. Let's say these will be The Sentinel and The Outsider (spiritual battle) OK, now what I believe to be one MAJOR in your face detail from Brandon is the fact that all shards have human emotions, traits or titles. If in the final battle, the last 2 major shards combine, I don't believe they will form Adonalsium because Adonalsium was just another human, THE HOLDER of the complete shards.
The last 2 shards have to form the most complete human trait, title or emotion: THE ONE. The One is complete, combining all shards into one, in a very subjective and humane manner.... and you know, even The One has its one opposite... THE VOID!