Your ability to open packs meanwhile is governed by a 12-hour timer, which you can accelerate with an in-game currency called Pack Hourglasses, and given the level of rarity of different cards - and the scarcity of packs - that means collecting 'em all is going to take a very, very long time
If that creature card has flash, you'll be able to cast it any time you could cast an instant, even on an opponent's turn
send 1 "Blackwing" Synchro Monster or 1 "Black-Winged Dragon" from your Extra Deck to the GY, and if you do, until the end of this turn, the targeted monster loses 700 ATK, also negate its effects
Faithless Looting, Cathartic Reunion and Shriekhorn fill your graveyard with dredgers and payoff cards and dredge those cards once your yard is full
Aragorn unites the Fellowship and the five colours of Magic into one unstoppable force