I decided to try out the THREAT room which I'd only used twice prior. In my first attempt I lost on the 3rd round. 2nd attempt with Spiderman and I passed the challenge in what I thought was very good play (leaving 1-3 enemies alive when ending my turn). I entered this with Dr. Strange who was my lowest lvl hero @ lvl 11 thinking it was going to be harder than the Spiderman run. I was completely wrong and it turns out Dr. Strange's deck was even better suited for this level. I cleared every round so the enemies never got a chance to attack back. Pretty funny considering I nearly backed out to go create items that would replenish hp when I realized I had none left.