Lands has almost no relevant cards in hand to discard since its gameplan runs through lands, Life from the Loam, and Dark Depths/Thespian's Stage, so Unmask and Cabal Therapy are nearly dead. Magus of the Moon turns all their nonbasic lands into Mountains, shutting off Urza's Saga, the Dark Depths combo, and utility lands like Wasteland and Karakas in one card. Stronghold Gambit can put one of our huge creatures (Griselbrand, Atraxa, Grand Unifier, Archon of Cruelty) onto the battlefield for free, but only if ours has the lowest mana value among the creature cards revealed. That usually happens when they reveal a non-creature card, which is likely since Lands runs almost no creatures (Icetill Explorer is the only one in their main deck). If they do reveal a cheaper creature, theirs enters instead and ours stays in hand. This swap shifts us from discard-reliant disruption to proactive, resilient threats that punish their land-based shell directly.