Taking the Dawnshard, known to bind any creature voidish or mortal, he crawled up the steps crafted for Heralds, ten strides tall apiece, toward the grand temple above.
–from The Poem of Ista. (Jasnah's note: I have found no modern explanation of what these 'Dawnshards' are. They seem ignored by scholars, though talk of them was obviously prevalent among those recording the early mythologies.)
You might be able to get him (Odium) to choose a champion. He is bound by some rules. All of us are. A champion could work well for you, but it is not certain. And ... without the Dawnshards ... Well, I have done what I can. It is a terrible, terrible thing to leave you alone.
Considering the fact that Shardblades and Shardplate are sometimes simply called 'Shards', it is possible that the Dawnshards refer to the Honorblades carried by the Heralds. Shallan, however, believes that the two objects are entirely separate.