I knew this would be messy before the game even started:
http://dominion.isotropic.org/gamelog/201210/12/game-20121012-185720-111adc88.htmlCards in supply: Fool's Gold, Golem, Governor, King's Court, Oracle, Pawn, Possession, Potion, Silk Road, Smithy, and Upgrade
But all that really mattered was King's Court, Possession, Governor and Golem (maybe Pawn)
The only real mistake Fire Penguin made was using his Governor to pick up a Gold. As soon as he did that he gave me the ability to gain provinces when I possessed him. With his Silvers and Pawns (and starting copper) I could gain 2 provinces and 2 duchies each time I possessed him (plus upgrading my own stuff - like a KC-> Province, or a Potion->Duchy)
The textbook play for this board is standard when Possession is a usable card - but highlighted like crazy due to Governor and King's Court.
You want to get to Possession and KC as fast as possible. Then you want to trash your own deck so the only thing you can do is possess the other guys deck repeatedly but are not able to buy anything yourself.
Ideally you want to get to a ton of Governors, a couple of KC, a Possession or two, and 4 copper and a potion (so you can keep picking up Golems). Then draw your deck with Governors (drawing the other guys deck at the same time), and play as many Possessions as you can on his newly big deck. Then use his deck to buy green (or remodel into it with Governors).
The only thing he would be able to do with your deck is buy Estates (and Golems. Golmes are a good defence if you get enough Possession density since they are dangerous to play).
Neither of us got to that textbook place, but we were both headed that direction.
It's a tough balance (and a lot of luck) to get the economy you need to get Possessions and King's Court and then trash down - and in this case the whole game was over in 11 turns - so you don't have a lot of time...
I did it this time by opening 5/2 - which let me get a Governor. And then using the Governor for draw only - I had 7 copper which was enough to get KC or Potion or more Governors. My biggest mistake here was likely buying any Pawns at all. The just give Fire Penguin the ability to get to $8.
Messy. But more fun than I thought it would be. And it really highlights how to play Possession in less extreme situations.
Ed