Knowledge Exploitation [Morningtide] Mountain they tap all lands with

they tap all lands with mana abilities they control and lose all unspent mana

Set: Modern Masters 2017 Type: Creature — Lhurgoyf Rarity: Mythic Cost: {1}{G} Tarmogoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1

each player discards their hand and returns to their hand each card they exiled this way

cast it without paying its mana cost

but my host would casually push it down before I could make out what it was

Knowledge Exploitation [Morningtide] Mountain they tap all lands withSet: Morningtide Type: Tribal Sorcery Rogue Rarity: Rare Cost: {5}{U}{U} Prowl {3}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.) Search target opponent's library for an instant or sorcery card. You may cast that card without paying its mana cost. Then that player shuffles.