blaagh

I have more info. If I view the party as a whole (using the button in the top right), Kyra and Merisiel are DUPED (see screenshot). So there's 4 total characters in the party (2 each of Kyra and Merisiel) which explains the weird numbers in the bottom. I cannot see any way to change the decks for the two phantom characters, so they have too many cards in their respective decks. This is what I assume is blocking me from advancing.

I have this exact problem. During Poison Pill I had to banish some cards. In the deck building phase after the scenario I don't have enough cards to make a complete deck. There are no cards in the bottom (in the "available" section) unless I drag them from one of my character's decks. It seems this is fatal, no way to advance.