Teferi's last ability means that in order for an opponent to cast a spell, it must be that opponent's turn, during a main phase, and the stack must be empty
Potatoes are the cards that set up the payoff
Ultimately, it takes the intervention of several planeswalkers to stop Emrakul

Adagia, Windswept Bastion Agadeem, the Undercrypt Ancient Tomb Arid Mesa Bazaar of Baghdad Blackcleave Cliffs Blood Crypt Bloodstained Mire Bojuka Bog Boseiju, Who Shelters All Bountiful Promenade Breeding Pool Cabal Coffers Canopy Vista Cascade Bluffs Castle Ardenvale Cavern of Souls Celestial Colonnade Cephalid Coliseum Cinder Glade Copperline Gorge Creeping Tar Pit Dark Depths Dark Depths Darkslick Shores Desert Deserted Temple Dryad Arbor Dust Bowl Emeria, Shattered Skyclave Evendo, Waking Haven Eye of Ugin Fabled Passage Fetid Heath Field of the Dead Fire-Lit Thicket Flooded Grove Flooded Strand Fomori Vault Forbidden Orchard Gemstone Caverns Glacial Chasm Godless Shrine Graven Cairns Grove of the Burnwillows Hallowed Fountain High Market Homeward Path Horizon Canopy Hostile Hostel Inkmoth Nexus Inventors' Fair Karakas Kavaron, Memorial World Kessig Wolf Run Kor Haven Library of Alexandria Lotus Field Luxury Suite Mana Confluence Marsh Flats Maze of Ith Maze's End Minamo, School at Water's Edge Mirrorpool Mishra's Workshop Misty Rainforest Morphic Pool Mount Doom Mouth of Ronom Murmuring Bosk Mutavault

Skip to main content SIGN IN Murders at Karlov Manor: Outrageous Robbery Edition: Murders at Karlov Manor Type: Instant Cast: Rarity: R Collector #: 0097 Target opponent exiles the top X cards of their library face down