From what I can tell the second booster is black triangle as well, but clearly a bit more difficult to verify
Despite their advanced intellect, some aven never quite shake their instinctive need to collect shiny baubles
201.3 If an effect instructs a player to name a card, the player must choose the name of a card that exists in the Oracle card reference (see rule 108.1) and is legal in the format of the game the player is playing
(It took me a while to make just the Guide
In these cases, its critical to remind yourself of the silliness of these buyouts and to remain focused on cards you do want to play
Activating the card requires you to declare a direct attack with a Monster with 1500 or less ATK, and then you discard your entire hand (which thankfully is allowed to be as little as 1 card), then excavate the top card of your deck and inflict 500 damage if it's a Monster and then you can repeat this up to 7 more times as long as you keep excavating Monsters