The current version of the card is much better for its cost imo.
It's not OP, because not all of us uses Poison deck, so it's a bit more... situational IMO
What if there were a bomb, that killed all creatures you didn't want on the board, destroyed all permanents, and drained your opponent's quanta? But it was only usable if the opponent had 7 entropy quanta and was using a SoG, on even days and odd months. It's situational, so that makes it not OP, right?\
The big issue is, if this lands against the right deck, it undoes an entire strategy. That makes it overpowered. It may be terrible in every other circumstance, but against those decks it works against, it's too good for 4 mana.