Cutpurse never helps you?
Menagerie. Edge Cased.
But I agree "on average" Cutpurse hurts.
Yes, I mentioned that there were edge cases in another post. Draw-to-X cards are another.
Mainly I'm arguing that it doesn't hurt nearly as much as many people seem to think, sometimes actually helps, and quite often does nothing much at all as far as the possessed player is concerned. Many players seem to think that Possession is super powerful and utterly crippling when they first learn about it, and they are surprised that it isn't classified as an attack. I certainly felt that way. But experience and logic shows that giving it the attack type would be silly. Most of the impact of Possession is indirect (changing your strategy just because it's there) or psychological (remembering the bad times when it cost you a Province far more often than the good or neutral).
but that's just not true. you can make your opponent have a bad next hand, and that's a powerful attack. not just with some cards, but all the time, just in varying degrees. yes, obv you can't do it if there aren't any other cards in the kingdom, but whenever you play possession there are other cards in the kingdom, and usually there is draw/trashing/sifting, because these are also the cards that make possession viable.
Sifting can allow the possessor to mess with the player's next turn, but draw and trashing don't except in extreme cases. As much as we love full-draw engines on f.ds, those do not happen every game. Even if such an engine is available, a smart player will only build that engine if it can get going before Possession hits. If that's not possible, a smart player will do something else instead.
sometimes possession does nothing. sometimes it hurts the next hand by 1 card, like minion (e.g. through courtyard). sometimes it absorbes key cards and puts them far away into your discard pile. sometimes it disrupts your engine and makes your next hand dead. sometimes it makes you pass/exile a key card. and sometimes it's a complete pin.
i don't know how much it hurts on average, but it's more than, let's say, militia, or spy.
You know what else can make you miss key cards? Tribute. And you are skipping the times when I get possessed with a poor hand, allowing me to play a good hand for my regular turn.
I think you are vastly over-estimating the power of Possession. That, or you are only considering the boards where Possession is worth buying
because of the factors that make it good. But do you buy Possession every time it's available? I doubt it. I skip it most of the time, because most of the time it is just a big Workshop.
Militia definitely hurts more than Possession. And Spy, weak as it is, more consistently hurts the other player in making them skip good cards and keep bad cards than Possession does.