So, one thing I'd like to do on this thread is repost older challenge cards in case anyone wants to help improve them.
My idea is to do it once a month so as to post multiple (4) cards at once, while also updating the first two posts of this thread (post 1: listing of all the cards; post 2: Secret History of all the cards).
I've gotten a little delayed, so let me post the 4 most recent ones now and I'll probably do the next post in a couple of weeks, so I can get on that schedule.
Anyway, here they are (followed by some comments):



Collector:Collector is similar to Improve. The main differences are:
• it allows you to "improve" any played card (so can be used to trash coppers)
• you have to decide as you play the cards, by setting possibly candidates aside
• setting aside can make you skip a shuffle which could be either bad or good (this was a last change in order to have the setting aside mean something; besides just helping Magic Lamp)
The main issue with Collector, as pointed out by faust, is that it would be possible to have a board (with no draw) and it being impossible to activate Magic Lamp. (Secret Cave is a cantrip, so even without draw, you could play, Secret Cave, Action #2, Copper, Silver, Gold, Magic Lamp, and activate).
So while Collector does help with the setting aside, it's not enough and, in its current state, is a bad design. Hopefully it'll be as easy as just making it a cantrip. See v0.4 below.
My biggest question is: is it worth keeping this card or keep trying to improve it? Or is having it exist with setting aside mostly just for Magic Lamp not interesting enough and I should drop efforts on it?
Stockpile:This one was a misunderstanding on my part of the challenge, but still got a decent review. I think play testing will help determine if 2 uses each time is enough or if it needs to be a little stronger. Overall, I think the concept of a "reloadable" Gold has merit.
Cabal:Some people thought this card was not very valuable, because you might have a board with no or only one other Night cards, but I think that a) even in the presence of one other Night card it does have value, and b) even without any other, it still could be worth buying since it can't be drawn dead.
It was compared to Royal Carriage and not as useful as it and I do understand that. I think my main objection is that most boards won't have Royal Carriage. And if the argument is well, the board might have RC, I think the counterargument is, the board might have Night cards (which are more likely).
Coven:The main concern for this one is how it would compare to other cursers. It was suggested to make it stronger or cheaper. I'm opting for cheaper and see how that looks. (I did also remove the non Attack clause, so now you can, for example, supercharge your Witches to gives 2 Curses - once per turn, of course)
So here are the updated versions for Collector and Coven:


I'm hopeful that by posting 4 at once, there'll be some more feedback for some of these cards. And honestly, even if the feedback is: "this design is just not worth iterating on" that would be helpful.