Missing sideboard cards? The full 15-card sideboard runs about $104.
Buy sideboard on ManapoolConsign to Memory counters colorless spells and triggered abilities, letting it stop Mishra's Bauble triggers or answer Bilbo's attack trigger while dodging Force of Will and Daze since it only costs {U}. Grafdigger's Cage shuts off Bilbo, Thief in the Night casting spells from the graveyard and stops Nethergoyf's Escape ability, both key resilience pieces for this deck. Omniscience is too slow and clunky against a deck built to disrupt your hand and race with cheap threats, so it comes out. Flusterstorm is weaker here since the opponent's key spells like Thoughtseize and Brainstorm resolve on their own turn when storm count is low, so it makes way for more targeted answers. Keep the core combo pieces intact since Show and Tell and Sneak Attack still present a faster clock than their Murktide Regent or flipped Tamiyo.
Eldrazi runs Chalice of the Void which can shut off our Lotus Petal, Brainstorm, and Ponder at X=0/1, so cutting a card that doesn't die to it like Stock Up (mana value 3, safer) for resilience is reasonable, though our real plan is to go over the top with Show and Tell/Sneak Attack into Emrakul or Griselbrand, both of which dodge Chalice entirely. Brotherhood's End sweeps their small Eldrazi tokens and can hit Chalice of the Void or Lotus Petal via its artifact-destruction mode. Grafdigger's Cage doesn't stop their gameplan much but is low-cost insurance; Flusterstorm is weak since this is a low-spell-count creature deck.
Ocelot Pride wants to go wide and race, so Abrade kills Guide of Souls or Ocelot Pride before they snowball, and can also blow up Wasteland-adjacent artifacts if needed. Hexing Squelcher protects our combo spells from being countered by anything they splash and lets our Sneak Attack/Show and Tell resolve reliably. Omniscience is too slow against an aggressive clock backed by Wasteland disruption, and Flusterstorm is weak since they're creature-heavy rather than spell-heavy. We keep the core combo intact since Show and Tell into Griselbrand/Emrakul is still our fastest clock against their pressure.