I thought of that, but in the end decided to go with a rigged explosion. As I said, I didn't want to out and out replace Explosion, but rather augment it. Krathos is correct, I think, in saying the card isn't quite balanced, damage-wise. My original thought was 3 damage to the field (as in all creatures) for the unupped, with a switch to only your opponent's creatures for the upgraded card. I think I like your ideas a little better. Particularly stacking it on pillars...I did not look at it that way. I endorse this mod.
I shall have another look at this card sometime in the near future. Any other input would be great.