the stupidest thing I've done so far:
1. 'deal 5 damage for each ethereal card you've played'
2. ancient relic that doubles damage for 3 attacks
3. upgrade
4. 2x upgraded 'deal 75% more damage on first attack each turn' power
5. hello test subject phase 3, here is 40x14 damage to your face
One run I managed to get my Thing up to like 80 or 90 health in the first few turns and just murdered everyone in one hit. Was hilarious but also really dumb.