Missing sideboard cards? The full 15-card sideboard runs about $101.
Buy sideboard on ManapoolDimir Tempo relies on sticking Murktide Regent, Nethergoyf, or Tamiyo and protecting them with Daze/Force of Will, so cheap unconditional removal that dodges counter mana investment is premium. Snuff Out can be cast for 4 life off Bayou/Swamp to blow out a freshly-resolved threat even when tapped out, while Fatal Push cleanly answers their small creatures like Orcish Bowmasters and Bilbo. Once Upon a Time and Sylvan Safekeeper are the weakest noncreature value pieces against a deck that isn't trying to kill us with burn or targeted removal, so they come out. Keep Thoughtseize and Wasteland in, since denying their own disruption and mana is still key to winning the race against their tempo plan.
Ocelot Pride Midrange goes wide fast with Ocelot Pride tokens, Ajani's Cat tokens, and Amped Raptor, so Fatal Push is excellent at killing the 1-toughness Guide of Souls or 2-toughness tokens before they snowball. Tear Asunder can be kicked to exile a problematic Ajani, Nacatl Pariah or Voice of Victory, and even unkicked it answers Goblin Bombardment before it starts picking off our team. Sylvan Safekeeper and one Once Upon a Time are cut since they don't interact with the opponent's proactive board development, and we need more cheap interaction to keep pace with their explosive starts.
Sultai Aluren's entire plan revolves around Aluren enabling free Atraxa loops and Show and Tell cheating in Omniscience/Atraxa, so Leyline of the Void (cast for free from the opening hand) cuts off graveyard-based value and recursion tied to their engine while also denying card-type fuel. Force of Vigor is a two-for-one against Aluren itself or any Omniscience/enchantment they land, often for free via its alternate cost. Thoughtseize is weak here since they're a combo-value deck that can rebuild through Brainstorm/Stock Up and isn't hurt much by single-card discard once Aluren resolves. Sylvan Safekeeper and Crop Rotation aren't impactful against a deck that doesn't attack our board or care about land destruction.