I just had an insight as to why cards like aquamancers and fire prisms are so annoying to me. Besides being virtually indestructible, unblockable, having potential to trigger multiple times a round (may require energize) and consuming no resources that is.
They have no waste. 4 hit points of damage generated by aquamancers or fire prisms always hit. Meteor's 4 damage could be wasted if used on a creature with only 2 health. Fire rain's potential damage is wasted if there is only one health 3 enemy on the board and 4 empty lanes. A ruby dragon overkills a kobo miner -- it doesn't carry the extra three damage to other creatures.