[@Salsa Verde]
The 'freebie' in the Codex does not 'disappear'. You can use it as many times as you want, in each combat post, but not double/triple up on it in a post, since there is only 1 of it.

And yes, if you have 2 copies of the same card, the effects will also double/triple up. So, if you were to have 3 copies of an elemental boost, it's +75% instead of just 25%.

[@DeadDrop]
Run out of cards? Never!

[@Rockette]
Dirty girl! Behave yourself.