I noticed during the myth deckathalon that when you conquer the tower, (Stage 4), you are able to purchase a crafting recipe for the Queen Calypso treasure card using runes! However, the bad news is, I am pretty sure you can only craft them inside the deckathalon towers. I tried crafting a TC at my card crafting station at home using a rune recipe I purchased in the fire deckathalon tower. I was not able to craft it there, so I assume you can only craft them at the card crafting station inside the actual deckathalon towers. You could ask any of your friends that ran this last myth deckathalon if they happened to craft any of those cards or at least if they bought the recipe?
If you are not in a hurry to get them, you will be able to craft as many QC treasure cards as you like as soon as the next deckathalon runs again! (you or whoever you know that purchased the recipe inside the myth deckathalon tower). It doesn't matter what school the next deckathalon is, as long as you have the TC recipe you can craft them all inside the tower on any stage you conquer.