Really, you should save crafting cards for when you wish to complete specific decks youre building, but ultimately, its up to you
Chaos: Whenever you roll Chaos, draw a card
This means that there is one copy of each of the three cards in existence, making them incredibly rare and valuable
However, the balancing of such a card can be difficult to make, so there is only one current Plot point at this time
Any deck I put together led by Saruman is going to have a sacrifice outlet so that I can choose to create a new Army if Id like
For those hunting Curios, its worth checking the list of all discovered ones here: Given the Site distribution limitations for constructed play, Id recommend new players consider starting with a Precon, or supplementing a Beta box with an additional box of another set and/or singles if you want to build legal constructed decks immediately