No matter which pack you purchase, each one has cards of different rarities
Usually the correct choice is to never take the offer, though for a table there has to be some implicit trust since to be the only opponent to take an offer gains that player an advantage over everyone but the offering player
Rarity is a tricky topic, but I believe it is one that can be streamlined
Weezings attack, Tackle, does a mediocre 30 damage for one darkness energy
They are rare and undocumented, presumably just a production variation that was overlooked
While its possible to build this out using just Final Fantasy cards, I had the most fun mining the most recent sets and by embracing the weirdness of Universes Beyond especially when I added Raphael and Leonardo from Teenage Mutant Ninja Turtles into the mix