I thought that the card game in 8 was fantastic. Much better than 9s (although it was still fun in 9).

I really think you're reading too much into it though. It doesn't need to make sense and follow on and all tie together nicely.

It's a Japanese trait I think you'll find - they just love zany and quirky fun things like this. Take monkey ball - absolutely pure and simple yet so brilliant. Cards is simple and yet addictive and entertaining. It's the Japanese way of adding a bit of light relief into the game and it's definately appreciated.

I doubt Square really cared how the cards fitted into the whole scheme of things.