For what it's worth, I had forgotten to put the on-gain rotating on Valhalla; it's there now, which might change your analysis a little. Thanks for the feedback though! It sounds like you might have missed that Privateer and Paladin are also worth VP? And I think the fact that Valhalla is strictly better than Province (and Paladin strictly better than Duchy) is fine because they're generally not going to be available during your buy phase unless you put some extra effort into it; but I could be wrong about that.
Yes, I missed the VP. With the vallahalla rotation, definitely makes it an actually pile, but I still think that if Paladin should do something other than just VP and exchanging.
I'd argue that getting a SoP is still useful as a gainer for the other stones. In particular, SoR still shines when used with SoI rather than SoP (both netting +$4 per play (was +$5 for SoI), with SoP providing an extra card and buy for the difficult setup). Uncontested, getting a SoP onto your tavern mat will likely take about 4 shuffles, and another to also get a SoR ready. A well-timed SoT of your opponent can delay that another shuffle.
Anyways, with a split pile of reserve cards I just had to create a reserve-replayer and a reserve gainer that gained onto your Tavern mat.
It is useful, but mainly as +3, +4, or +6 coin and +buy instead of a workshop. I agree that setting it up is difficult, but I am saying that once you have 2, you don't need a third (unless you don't have one on your TM, and bought 2 so you could more quickly grab the third, and maybe a SoR), nor do you want a single one for its main purpose.
Uncontested, and with perfect luck, you get a gamble T1 and follow with a SoT. This lets you draw SoT T2 and use it T3. T4 you shuffle again, letting you draw SoT and use it T5. T4 get gamble. This gets you to SoP, with a silver and 3 coppers to purchase it. T6 you get SoT and SoP, letting you grab a SoP to your TM and set up for rotation next turn. Grab gamble and expedition. T7 you have 1 card left, so you pull up SoP. SoT a card to rotate to SoR to grab a SoR. Get gambles and end with expedition in order to cycle your deck, quickly grabbing another 2 SoR on T8 (one with a buy and one with SoP.)
Carousel
Action/Duration/Carnival - $2
+$3
+1 Buy
For the rest of the game, at the start of your turns, rotate the Carnivals. If this puts a Duration on top, +1 Card.
Juggler
Action/Carnival - $3
Do all three in any order:
Draw until you have 5 cards in hand;
Discard a card;
Trash all but 3 cards in your hand
Slippery Dip
Action/Carnival - $4
+2 Actions
Choose one: +1 Card and rotate the Carnivals; or +$2 and discard a card.
Funhouse
Action/Duration/Carnival - $5
At the start of your next turn, +$3 and +1 Buy. Until then, when a pile is rotated (using the word "rotate"), +1 Card.
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Concept: You almost definitely want a Carousel, which sets the pile spinning. Each of the cards in the pile contains something useful and it might be the only example in the game - Trashing, +Actions, +Buy.
I like this pile, especially with carousel rotating every turn, but I think there should be +(1) or +1 buy on non-duration carnivals. Funhouse may not scale well with multiple players.
