Adrenal Frenzy says "Reveal the top 3 cards of your Draw Pile. From the revealed cards, you may add all Apex cards to your hand and discard the rest." If you have fewer than 3 cards left in your draw pile, do you get to shuffle your discards to create the new draw pile and keep revealing until you reach 3 cards? Or are you limited to what's actually in your draw pile when you first play the card? I've been reshuffling and revealing a total of 3, but then second-guessed myself.
Typically, in almost all deck building games, the rule of thumb is that if you ever have to draw a card, for any reason, and your deck is empty, you shuffle your discard to make a new deck. David posted the quote to confirm, but it is very rare in a deck building game for this to not be the case.
And never include cards that have been played this turn as part of your discards. If you play a lean deck, it is not too difficult to run out of cards to draw -- when you do, then I guess you just do all that you can.