I originally posted this card in the Power Grid Promo thread. Today I decided to playtest it in a few games against myself and see how it worked. I was pleasantly surprised. Here's the card (slightly altered after playtesting):
Floodgate
Types: Victory
Cost: $4
Worth 2 VP.
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When you gain this, you may set aside all of the cards from your hand face down. At the start of your next turn, return them to your hand.
When I designed the card, the idea was a sort of one-shot Tactician effect. I figured that you'd buy them near the endgame in order to save your unplayed Treasures for next turn, or in the mid-game to put together a combo (like Treasure Map or Tournament/Province). And you can do those things.
But it turns out the real power of the card is to keep your unplayable cards (pure Victory cards, Curses, etc.) from being shuffled back into your deck. As long as you manage to buy a Floodgate every turn, you can perpetually keep these undesirable cards out of your draw pile. It's sort of like a mega-Island. However, if you ever fail to buy a Floodgate (or the pile runs out), bam! Your deck is immediately flooded with crap. The idea is to time it so that you end the game before that happens.
It's a real game-changer of a card. It's interactive in that you can mess with your opponents' timing by depleting the pile. It's unique in that it's a pure Victory card that you'd buy
to help your engine.
I think it'll need more playtesting in order to determine whether it needs a cost tweak or a limit as to how many cards are set aside. I like the concept, though. Let me know how you feel about it and if it creates any game-breaking combos I haven't yet thought of. Thanks!
EDIT: Second iteration:
FloodgateTypes: Victory
Cost: $4
Worth 2 VP.
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When you gain this, set aside up to 5 cards from your hand. At the start of your next turn, return them to your hand.