Mono-Green Landfall's whole plan is cheap creatures like Llanowar Elves and Sazh's Chocobo compounding with land drops via Earthbender Ascension, so Day of Black Sun sweeping the low end of their curve is excellent. Flashfreeze counters almost every spell they cast. Spell Pierce, Spell Snare, and We Say Thee Nay! have weak targets against a creature-heavy, noncreature-light deck, so they come out for the sweepers and countermagic that actually answers their gameplan. Watch out for Icetill Explorer's extra land drops accelerating Ba Sing Se online faster than expected.

This is a Dimir mirror where hand disruption is at a premium, so Duress comes in to strip their own Duress, removal, or Day of Black Sun before it lands. Strategic Betrayal answers their biggest threats, forcing an exile of a creature like Doomsday Excruciator or Superior Spider-Man along with their graveyard, which is especially valuable against Superior Spider-Man's graveyard-copying ability. Nowhere to Run and We Say Thee Nay! are cut since this matchup comes down to card advantage and disruption rather than combat tricks or soft counters that ask them to pay extra mana they usually have. Keep Requiting Hex against their early creatures and Bitter Triumph as your removal suite against Doomsday Excruciator.

Azorius Tempo leans on key noncreature spells like High Noon, Airbender Ascension, and white removal like Erode and Avatar's Wrath, so Duress effectively strips these crucial noncreature targets from their hand. Disdainful Stroke is well-positioned against their few expensive spells while their creatures are mostly small, so Nowhere to Run's -3/-3 is less necessary and comes out along with Spell Snare to make room for broader interaction. High Noon restricts both players to one spell per turn, so prioritize efficient, high-impact plays and use Kaito, Bane of Nightmares to apply pressure they can't easily remove. Enduring Curiosity is a strong mirror-breaker since it returns as an enchantment after dying, dodging their removal suite.