Cthulu, Great Dreamer

Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, all cards revealed this way are put into graveyard.

Horrors you control have Dream.
(When a player would take damage from a card with Dream they instead add counters equal to the damage they would have taken, then mill equal to the number of counters on themselves at end of combat. All Dream counters dissipate after combat.)
"The oldest and strongest emotion of mankind is fear