Missing sideboard cards? The full 15-card sideboard runs about $302.
Buy sideboard on ManapoolOcelot Pride Midrange goes wide with small white/green creature tokens (Cats, Warriors), making Glistening Deluge's -1/-1 (and additional -2/-2 vs white/green) a great sweeper against their 1/1 and 2/1 tokens and Guide of Souls. Dauthi Voidwalker is a great evasive clock that dodges Swords to Plowshares' exile only when they choose not to use it, and punishes graveyard dependence while providing an unblockable (shadow) attacker vs their ground-based creatures. Mockingbird is weak here since their best threats (Ocelot Pride, Ajani) are cheap and not worth copying, and Ponder is less necessary against a deck that doesn't contest the graveyard plan as hard as combo/control matchups. Keep Fatal Push and Orcish Bowmasters in, as they answer small creatures and punish their own card draw effectively.
Dimir Tempo is a mirror-adjacent matchup sharing many of our own tools (Daze, Force of Will, cantrips), so graveyard hate from Dauthi Voidwalker is very strong, exiling cards before they reach their graveyard to shrink Nethergoyf and deny its escape while providing an evasive clock. The extra Fatal Push copies help answer their early threats like Nethergoyf, Bilbo, and Orcish Bowmasters cheaply before they snowball. Kaito, Bane of Nightmares has mana value 4, so Push only handles him with revolt, and he is only a creature on his controller's turn, so don't plan around Push for him. Ponder and Wail of the Forgotten are cut since this matchup is more about efficient interaction and pressure than extra card selection, especially with both decks fighting over the same resources. Keep Orcish Bowmasters and Daze in since both sides are cantrip-heavy and punishing/protecting threats matters significantly.
Sultai Aluren is a combo deck relying on Show and Tell, Aluren, and Stock Up to assemble a quick Atraxa/Acererak/Emrakul game plan, so free countermagic is critical. Force of Negation can be cast for free on their turn to stop Show and Tell, Aluren, or Omniscience, and Consign to Memory counters triggered abilities such as Atraxa's enter trigger, Acererak's enter trigger, or Emrakul's cast trigger that gives them the extra turn (Emrakul, the Aeons Torn itself can't be countered). Mockingbird is weak since copying their creatures (Atraxa, Acererak) isn't a good use of mana when we need to be interactive, and Wail of the Forgotten's upside is lower against a deck we need to be proactive and disruptive against rather than grinding card advantage. Keep Daze and Force of Will in as they are premium free interaction against this matchup's key enablers.