Wanted something heavy on theme? Here we go!
Christmas - Event $4
Choose to gain a Grinch; or both a Gift and a card costing up to $4. Each other player that has Naughty gains a Lump of Coal; if they don't have Naughty, they gain a Gift.
An event that acts like a sort of messenger if everyone plays nice, but ends up attacking everyone if they are Naughty. How do you get Naughty?
Naughty - State
When you play an Attack card, take Naughty.
Ah, so you get Naughty by being Naughty. Seems thematic.
So that explains that. But what a Lump of Coal vs a Gift? And what's a Grinch? A Grinch is a laboratory attack (that's where Naughty comes into play). And a Lump of Coal is a better Confusion and a Gift is a weak wish.
Gift - Action - $4*
+1 Action
Return this to the Gift pile, if you did, gain a card costing up to $4.
(This is not in the Supply.)
Lump of Coal - Action - $0*
Return this to the Lump of Coal pile.
(This is not in the Supply.)
Grinch - Action Attack - $6*
+2 Cards
+1 Action
Each other player with at least 5 cards in hand discards a Gift or reveals a hand with no Gifts. Then, each other player discards down to 4 cards in hand.
(This is not in the Supply.)
(There are 10 copies of each of these. Seems about right. Sometimes you will run out of gifts to give.)
So yeah, you buy Christmas and everyone gets presents, and hey you get one two, and also get to open one immediately! Or you could get a grinch to take away people's presents. Grinch is a powerful card in that Laboratory is a powerful card. The attack is annoying but amounts to a slightly stronger urchin overall, so not terribly painful. Plus, normally you can only be hit once by it. Of course, playing a Grinch opens you up to other people attacking you by buying Christmases. It's worth noting that giving the other players Gifts is nice, but they have to wait to play the card and then another shuffle to use the card they exchanged the Gift for. So, it is slightly weaker of a boon to your opponents then it may seem. And you, if you're naughty, you don't mind giving them gifts because you can force them to discard them with your Grinches and never even be able to open the Gifts. Now
that isn't the Christmas spirit!
So, at first buying Christmas does something positive for the other players. If they stay nice, it keeps doing something positive. But if they get Naughty, then it no longer does. Okay, those are my cards! Always open to feedback.