Missing sideboard cards? The full 15-card sideboard runs about $109.
Buy sideboard on ManapoolConsign to Memory is a colorless-spell/triggered-ability counter, so it stops Orcish Bowmasters' enters-the-battlefield and draw-punisher triggers as well as colorless spells, which is valuable against their value-token engine. This matchup is mostly a race where we want to resolve Show and Tell or Omniscience before they overwhelm us with Cats, so we trim slower, non-essential cards rather than core combo pieces. Veil of Summer is tempting but their deck is mono-white with minimal blue/black spells to punish, so it stays in the sideboard. Keep pressure on resolving a fast Atraxa or Emrakul since their removal (Swords to Plowshares) is the main answer to our win conditions.
Veil of Summer is excellent here, blanking Thoughtseize and Force of Will/Daze while drawing a card off their Daze or a black discard spell. Surgical Extraction can strip a key piece like Murktide Regent or Tamiyo from their deck/graveyard once you see a copy. We already run 3 Veil of Summer and 4 Force of Will maindeck, so the swap is minor; Hedge Maze is a slow dual that can be cut for Surgical since it enters tapped and this matchup rewards speed. Keep City of Traitors and Ancient Tomb since Wasteland pressure makes fast mana even more valuable.
Doomsday is a glass-cannon combo deck racing us to resolve Thassa's Oracle. Trickbind is a strong answer here: Thassa's Oracle wins through its enters trigger, and Trickbind counters target triggered abilities. Split second also means they can't respond with Force of Will or Daze once it is on the stack, so hold it for the Oracle trigger. Echoing Truth can return their Thassa's Oracle (and any other permanents with the same name) to hand, but the win trigger is already on the stack by then, so treat it as a secondary, situational answer and lean on Trickbind for the combo itself. Intuition is awkward versus a deck that can simply pick the worst of three options, so it's fine to trim. We are still the faster combo deck on balance, so prioritize protecting our own plan with Force of Will over leaning too hard into interaction.