No, it's slightly OP in it's current form. I think the best balance is "target pillar stack becomes ruined pillars"
The ruined pillars are perfect at 2
. They don't need to come down at all, even if you weaken the card down to single targeting.
I don't know about the whole "able to target shard stacks" thing. It's a tedious tack-on extra that doesn't feel right, but that's my opinion.
Also, I think the name is awesome. Mechanically and thematically this idea is original and solid.
thank's

, i agree it shouldn't be able to target shards (or at least the theme wouldn't feel right), but i think that if i make it only be able to target stacks, it would make it inferior to "quicksand", that costs much less, destroys 3 pillars and doesn't create a "consolation prize"
besides this card not having a high "spam value" as targeting ruined pillars won't do anything (unless i change it so targeting ruined pillars with this destroys them)