Card: Deal with the Devil
Common
Cast: 8 turns

Caster can convert any rare card to an uncommon card, or any uncommon card to a common card.

Or;

Any 10 common cards to one common card with a 50% chance for success.

Randomly?

Or does it act like Duplicate in nominating the card you want?

No - ye select, much like duplication.

I like it, I can think of many useful swaps.

It has my support.

I like the concept and idea, though it would most likely lead to folks turning cheap and worthless rare/uncommons into more expensive voodoo a tier down. The market would probably go through a roller coaster like ride for a while, though it would stabilize eventually. I would suggest maybe add a chance for the voodoo to give a different card then the one chosen. Something like 50% chance you get the card you picked, 50% chance it's random. The values can be changed, but I do think there should be some risk in downgrading cards. This is a deal with the devil-should be a bit risky in my opinion.

edit-for my vote, add a bit of risk and it's a big +1 from me. No risk then I would say no. Risk needn't be high honestly 20% would be what I would suggest, but anything from 10-50 is fine by me.

edit-2 also think you should either scrap or rework the 2nd effect. It's very similar to gris gris, except common and way worse.

all i see this card doing is devaluing most valuable common/uncommon cards like charity donation or transport immigrants. i think that less ways there is for one to obtain any specific card, the better.

but since there is likely one or two million unused cards, some way to benefit from them all would be welcome. maybe different gris gris with different outcome when using uncommon/rare cards. but this i find to be too specific, even if its rare card.

I agree with Cutpurse on this.

On the other hand, I, too, see the need to do something about all those worthless cards. Hopefully we can remove a few. But maybe something like a "refund" would work better than the "Deal with the Devil"? A pack costs 20 credits and gives you 1 rare, 4 Uncommon and 10 common. Perhaps you can ask for a "refund": It costs you 1 rare, 4 uncommon and 10 common cards of your choice. In return, you get a small amount of credits, maybe 3 or 4?

I would rather see "worthless" cards be either buffed or completely re-designed so as to no longer be worthless. Not necessarily make everything amazing, but at least not worthless in the sense that no one uses them

Fertile lands is a great example of retooling an old worthless card into something with the same flavor but with real value. It is also a bit extreme in the current market environment and not a target "power level" - maybe market forces will one day reduce its value back to reasonable levels for an uncommon...