Factory Press

This has been working well for me since the last update - got me through all three Diamond levels with only a handful of losses.

Its power curve is strictly aggro, but the ongoing benefit of Golem Press, the extra draw from Katanas and Quartermasters, and the couple of mid-game cards in the Market let it hold its own in some matches that drag out to 10-11 turns. Most matches are over by turns 4-6.