Like nearly all of the mini expansions in the collection, these were designed strictly for the two-player mode, meaning that solo players have to leave them to rot in the matchbox alongside the useless red gem token. I wasn't having that and I use them anyway, even just as placeholders.
Elixir **
Tidies up the tokens in the two-player mode (tidying up is a preoccupation in this game) by giving them homes that later give someone a bonus. I use them as more attractive automa shelves, ignoring the icons.
Zero **
I hadn't realised the number 0 cards were officially a "mini expansion" when they came as part of the main deck. They don't work in the solo game. I use them for my starting shelf and when drawing an extra face down card to close a shelf, which extends the game slightly and presumably breaks the maths.
Rebis Solo: Ruby Variant (Fan Variant) ***
An unofficial variant that finds a use for the red gem in solo play and makes so much sense that I don't know why it wasn't there originally. Not that I actually manage to reach the gem in practice, but it's nice to see it, and it helps to track where I'm up to.
