Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard
In case you're questioning how good this card might be, take a look at what happened to its price

Commander Creatures Avian Oddity Bloodhaze Wolverine Drannith Healer Drannith Stinger Faerie Vandal Flourishing Fox Greater Sandwurm Imposing Vantasaur Irencrag Pyromancer Lava Serpent Loch Dragon Niv-Mizzet, Parun Prickly Marmoset Rielle, the Everwise Rooting Moloch Sanctuary Smasher Savai Thundermane Snare Tactician Splendor Mare Thieving Otter Valiant Rescuer Noncreature Spells Coordinated Charge Frostveil Ambush Hampering Snare Memory Leak Migration Path Monstrous Step Ominous Seas Raugrin Crystal Reconnaissance Mission Shark Typhoon Unpredictable Cyclone Will of the All-Hunter Wilt Zenith Flare Lands Blood Crypt Breeding Pool Command Tower Fabled Passage Godless Shrine Hallowed Fountain Indatha Triome Ketria Triome Raugrin Triome Sacred Foundry Savai Triome Steam Vents Stomping Ground Temple Garden Watery Grave Zagoth Triome 2 Plains 3 Island 3 Mountain Cycling in Commander The cycling mechanic has been around since Urzas Saga , so playing cycling in Commander gets you access to a host of new payoffs

Featuring three cards based on the fire-and-flying type and some metallic items, many have already pre-ordered and impacted availability in a major way
Of course, other cards joined it at the same time, but this is the one that sparked a need for a ban list