After losing 6 in a row on T50 last night with fire rush, I got bored and built this to grind some AI3. The only match I lost was my first one because I forgot to change my mark. I was worried about protecting creatures on the board, but burrow works for that and even with the halved damage, you can unburrow to finish somoene off. Most of my matches with this deck run 60-90 seconds. It's fast. Boring? Maybe, but losing the majority of my T50 games because I can't afford to upgrade other cards is even more boring.