1. Player's deck is set to (code), regardless of whether they own any cards. Mainly useful so I can build a tutorial questline, though usable for lots of other stuff too. Actively have things I want to build (tutorial questline) being designed, so more interested in this one than a lot of other stuff.
2. Player's deck must/must not contain (stuff), where stuff is one or more cards, elements, or card types. Also, player's deck must be between X and Y cards, overriding normal restrictions.
2a. If we don't already have support for modified player stats (draw/mark/etc), that too
2b. Also, let's add a feature for invalid deck message. Instead of having it be a dependency so it's only visible when you have a valid deck, I'd rather have the quest available and visible and, when clicked on, it just kicks out a message explaining the deckbuilding rules. Similar screen style to start/end text.
3. Expanded rewards - randomized rewards from a pool, support for multiple rewards at once (i.e. both gold and cards)
3a. Possibly support for loot tables (as in X draws from table A, y draws from table B, etc). Good way to standardize rewards.