MArcomage

I like the idea, but it's nearly non implementable.
To create this card you have first to simulate a standard draw within the card code so that the card knows what's coming next.
About the card, I suggest to make it zero cost.

I don't have a standalone marcomage on my pc, but I beg to differ about nonimplementability.
What about if i rephrase?

replace all cocoon in hand with a card from your deck? :)

Even more - with non-rare from your deck

The next card is chosen after the card effect if card doesn't effect the draw. What you could do is to override the standard draw via card effect.