I don't know if there's anyone here that has played this game or not, but myself and a couple of friends started this for the first time and are kind of stuck on something (And yes we're going thru the instructions, and no it doesn't say what this is for) but at the bottom of each card are coloured cubes, which are all power dice, but there's a purple one, and there's no purple dice in the game at all - and basically my question is, what is that purple cube on the card, what's it for, etc etc? If I could get help on this before Monday at lunch, that'd be great. Thanks.