Hello. This is my first attempt at a fan card. I was thinking about a duration card that lasts more than one turn and provides a repeated benefit as well as incurring a repeated cost. So here goes:
Demon
$4 - Action-Duration
If this is in play at the beginning of your turn +1 Card.
If this is in play at the start of your cleanup phase, trash a card from your hand. If you do, leave Demon in play. If you don't, trash Demon and gain a curse.
Maybe the wording would be better as:
Demon
$4 - Action-Duration
Now and at the start of every subsequent turn, +1 Card
If this is in play at the start of your cleanup phase, trash a card from your hand. If you don't, trash Demon and gain a curse.
I'm not sure if this wording encounters the weird throned feast behavior where, because Dominion doesn't have a "lose track" rule, the card continues to operate even after being trashed. Also, is it weird to have an "if you do/if you don't" when there's no may. The idea is that it forces you to trash if you can, but if you can't, you lose the card. Maybe it would be better with "may."
So sort of like an alchemist or a permanent caravan except that you have the cost (or benefit) of trashing.
Thoughts? I've had no opportunity to playtest this. Feel free to inform me that it is the stupidest idea ever, but please try to say it in a nicer way and explain why.