"Yippie-Ki-Yay, Motherfucker!"
The Original Shard deck had issues since multiple
Shard of the Spire don't add anything.
The introduction of the merchants means you are able to play the deck with just 1 Shard in your market, removing the issue of sitting on a shard in opening hand, or having two useless ones on hand later on.
Another new addition was the introduction of the
Momentum Builder which works out as an 10/10 when used with the Shard.
The main plan of the deck is to play defensive until you get a merchant and get hold of a
Shard of the Spire and then start pumping out cheap big dudes. Protect them using
Stand Together and once you have enough damage on the board you can equip a
Sword of Unity to give your biggest heavy hitter a way to deal face damage enough to end the game.
Accelerated Impact in the market provides an additional surprise win condition for the bad luck times where you just end up with a bunch of 0 attack minions on the board.