Missing sideboard cards? The full 15-card sideboard runs about $316.
Buy sideboard on ManapoolDimir Tempo wants to land a resilient threat like Nethergoyf behind Force of Will and Daze, so a fourth The One Ring gives you a redundant, indestructible card-advantage engine that outgrinds their disruption once resolved. Dismember is efficient, cheap removal for Nethergoyf or Bilbo, Thief in the Night that minimizes tempo loss. Eldrazi Confluence is clunky at four mana against a deck built to interact at instant speed, so one copy comes out. Keep Force of Will and Force of Negation at full count since this is a battle of free counterspells and resolving threats first matters most.
Eldrazi is a colorless creature-based beatdown deck full of big bodies like Reality Smasher and Sire of Seven Deaths, so Dismember's -5/-5 is efficient, cheap removal that answers almost anything they play. Chalice of the Void on 1 or 2 can shut off much of your cheap interaction, though it does not stop Force of Negation since its mana value is 3 regardless of whether alternate casting costs are paid. Sink into Stupor only bounces one permanent and doesn't permanently answer their resilient threats, so it's trimmed for cheap removal. Ensnaring Bridge can lock out their bigger creatures once you're stabilized on board presence.
Ocelot Pride Midrange wins with a wide, resilient board of Cat tokens plus Voice of Victory and Ajani, so Barrowgoyf's deathtouch and lifelink give you cheap, repeatable trades that gum up the board while Kozilek's Command and Giant's Boulder handle removal duties. Force of Negation is weak since most of their pressure is creatures, not the noncreature spells it counters, and Eldrazi Confluence's -3 toughness mode is inefficient against their many small tokens needing per-target answers. Dismember is a clean, cheap way to remove Ajani or Guide of Souls before it snowballs. Keep The One Ring and Karn for card advantage since this is a grindy matchup, not a fast combo race.