(2/25/2015) You can't reveal more than one Dragon card to multiply the bonus
Recommended for: Collectors looking for special, hard-to-find cards If you enjoy foiling out your decks or collecting alternate-art cards, consider cracking some Collector Boosters
The Sapphire glimmers tend to be a little more advanced, requiring some strategy and creativity to be effectively used
(2022-06-10) If an object becomes a copy of an object that has an Adventure, the copy also has an Adventure
For most decks, being restricted to only cards that cost three or more means that Keruga, the Macrosage has the same exact issue as Gyruda, Doom of Depths: you only get to play a single card over the first three turns of the game, leaving you in a position where you're often dead to aggressive decks (this gets even worse in older formats, which are faster and place a higher value on efficiency)