Hail, fellow 17th shardians!
So, I'm not sure if someone has posted this yet, but I realized something as I was skimming through the end of Oathbringer. I looked upon page 1136 and found a quote when Dalinar smashes all of everything together. After he did that a parshwoman asks who he is. He responds with "I am Unity". An important thing to note for this theory is that every shard has its name capitalized. Preservation, Ruin, Harmony, Odium, Honor, Cultivation, etc. Noting this, and seeing how Unity is also capitalized, and how Odium has begun to fear Dalinar, I think that Dalinar will take up the shard, should it exist, of Unity. I dont really know how it would work very well, but maybe Dalinar would take up Honor first, which is more obvious with the fact that he summoned that perpendicularity. I'm not entirely sure, though, if it will be a combination of Honor and something else, or if it is an entirely different shard.
That is about as much as i could find regarding this theory.
Please leave criticisms or other supporting facts, if you could.
That would be nice.