This week, there's no nice way around it; we're going to kill a deck.
OK, kill is too strong a word, think more rebalance. Not nerf it to the point that no one uses it but make adjustments so that it is not super duper powerful. It will still be around but not quite as potent.
Also, we are looking for one, and only one decktype. You can describe a few with something like Kill Piles or Discard Manipulation but things like Lego Starfleet might be too big a net.
Which one (and only one) deck do you want to have magically readjusted?