Is Exodia a really good card?
1: It would depend on how and where you play. If you’re looking to play competitively, in Hobby Leagues, Shonen Jump Championships, or Regionals I’d strongly advice against it. Even some of the best players have problems consistently activating Exodia’s effect. If it’s mostly for goofing around with friends or for fun duels at the local card shop, then by all means go ahead. 2: You’re never guaranteed the cards when you buy them in boosters, unless you’re buying a lot of them, and the cards you’re looking for are a lower rarity. Most of the time, you’d be better off buying the cards individually.