mtg each player discards a card Discard any number" rules citing : r/mtg then draws that many cards minus one. Here's a question and an

Crovax Rarity: Rare TYPE: Vanguard SUBTYPE: - CMC: 0 Mana cost: USD: $5.63 EUR: 4.70 TIX: 0.00 EDHREC RANK: - Whenever a creature you control deals damage to a creature or player, you gain 1 life

Every Secret Lair starts with its concept, Heggen explains, and from there we then look to the cards

Now thats a combo

I chose to draw the cards

You can think of it as more direct damage in Voltron aura strategies, or a slow win condition for value decks that use Doomwake Giant or Anikthea, Hand of Erebos

Because of the way Zacks sacrifice ability is structured, you can technically use it during combat, meaning you can block an attack and trigger it to cancel out the attack altogether