Thanks!
One of the pros is that it opens lots of new synergies with cheap (non-destruction) permanent-targeting.
However, consequently, one of the cons is that until such mechanics enter the game, this card is just a situational Deflagration.
Also, I was thinking of interactions with permanent stacks (like frosted pillars + earthquake).
Right now, as I interpret it, no additional permanents would be destroyed.
Now that I think of it, perhaps I should allow the "frosted" status to stay on the stack even if one permanent is destroyed?
This would grant in-game uses against pillars, bonewall, and shards.
The thing is, I don't know if it overcomplicates the card, and/or if it necessitates I change the card text to "If target permanent stack is 'touched' by anything, one permanent is destroyed."