A roguelike deckbuilder with sideboards sounds soooo cool. Like imagine the first area has enemies with no sideboard, but after you beat the first boss and move to the next area they start sideboarding between rounds, but you can too, and there could be items you can choose that increase your sideboard size or let you see what the enemy boards in. You could build a deck with a transformative sideboard to try and get around the enemy sideboarding. Sounds like it could be a really cool design space for the genre.
