Missing sideboard cards? The full 15-card sideboard runs about $66.23.
Buy sideboard on ManapoolConsign to Memory is premium against this colorless-heavy Eldrazi shell, countering Kozilek's Command and colorless Eldrazi spells like Emrakul, the Promised End before they resolve. Wrath of the Skies sweeps their small utility creatures like Formidable Speaker, Icetill Explorer, and Eldrazi Spawn tokens before they ramp into bigger threats. Thraben Charm and Ephemerate are lower-impact here since this matchup is decided by disrupting their ramp and answering big threats rather than small creature tricks; Voice of Victory's tokens also struggle to attack into their blockers, even though opponents cannot cast removal spells like Unholy Heat or Kozilek's Return during your turn to destroy them. Keep Solitude and Galvanic Discharge as our best tools against their large individual threats.
This is the mirror match, so bring in Wear/Tear to answer their copies of Blood Moon (which would strand our nonbasic-heavy manabase) via its enchantment-destroying half, and to hit Goblin Bombardment if needed. High Noon slows down their explosive multi-spell turns, restricting them to one spell per turn same as us, which is a fair trade since we can sequence around it with efficient one-drops. Thraben Charm gets cut since we're less likely to need graveyard hate against a mirror that isn't graveyard-centric, and Ephemerate is a lower-impact card when both sides are racing with removal. Keep Solitude and Galvanic Discharge in since they're premium removal against their identical threat suite.
Consign to Memory is a strong include here, countering their many colorless spells: Mishra's Bauble, Tormod's Crypt, and Engineered Explosives. It can also counter Mox Opal as a colorless spell, though it can't counter Kappa Cannoneer, since that creature is always a blue spell regardless of how it's cast. Wear/Tear destroys their key artifacts and enchantments like Urza's Saga, Mox Opal, or Kappa Cannoneer, hitting a deck that is almost entirely artifact-based. Ephemerate and Goblin Bombardment are weak since our creatures aren't the axis of the fight against their fast artifact aggro, so replace them with proactive artifact disruption. Prioritize removing Kappa Cannoneer, since it grows quickly and becomes unblockable for the turn each time it or another artifact enters.