Death and Taxes leans on Aether Vial, Thoughtseize, and cheap efficient creatures like Stoneforge Mystic and Phelia, Exuberant Shepherd, so Trinisphere and Chalice of the Void set to 1 remain excellent against their cheap spell suite, though note Aether Vial's ability to put creatures onto the battlefield bypasses casting and is unaffected by Chalice. Eldrazi Confluence's exile-and-return mode is flexible interaction, able to remove a problematic Skyclave Apparition from combat or reset one of our own permanents in response to their removal. Sphere of Resistance taxes their spells that Trinisphere doesn't already tax to three mana, making their pricier threats and answers harder to cast. Once Upon a Time is weaker in this grindier, disruption-heavy matchup, so it and a land come out for more impactful sideboard cards.