I don't think I heard it somewhere. But as we still don't know where and who are all the 16 shards, is it possible the the Dawnshards hold Shards of Adonalsium in some way? I mean it would be very useful to hold the power of a Shard without the consequences of losing yourself to the Shard's nature. And the Dawnshard are said to be tools the could destroy world, I can't imagine anything so powerful than Shards themselves.
Just a thought I had and I wanted to hear what you thought about it or if you have any ideas that could hold better than mine.