Hey! Thank you for your comment.
We used the Dialogic system, at first I was planning to make one on my own but in order to coordinate properly with our writer we settled on using this plugin. Would I recommend it ? In the current state of things no, because we had quite some issues with it, and required patch-ups here and there. But apparently they're working on a 2.0 version that seems promising.
As for the use of the wild card I cannot tell you because it would eventually spoil branches of the story. I can only say that the interpretation of the wild card is not literal.
And If I may ask were did you get stuck? Ideally DM on Discord (to not spoil the game here :p)