Mainboard (60)
Creatures (8)
Instants (10)
Sorceries (12)
Artifacts (4)
Enchantments (6)
Dimir Tempo is your most hostile matchup — Thoughtseize strips your combo pieces before you can assemble them, Wasteland denies your blue mana, and both Force of Will and Daze counter your Show and Tell or Aluren. Post-board, Veil of Summer is your best card, blanking Thoughtseize and countermagic on the same spell that resolves your engine. Consign to Memory handles Orcish Bowmasters triggers and any post-board Surgical Extraction that targets Aluren or Atraxa. Force of Negation gives you free interaction on their discard or counters without tapping out. You trim some acceleration (Lotus Petal, City of Traitors, one Omniscience) because the game will go longer under their disruption and you need more interactive tools — Atraxa remains in because it's a resilient threat that wins through disruption if you resolve Show and Tell.
This is a mirror-style combo race where both decks are trying to resolve a Show and Tell or Aluren before the other. The key tension is that your opponent's Sneak Attack gives them a backup plan that bypasses the stack entirely, so you need to prioritize protecting your own combo while being able to disrupt theirs. Veil of Summer comes out because your opponent is on blue and red — not black — making it largely dead, while Consign to Memory and Force of Negation give you additional hard counterspell coverage against Sneak Attack activations and opposing Show and Tells. Boseiju has limited targets in this matchup since your opponent runs few relevant permanents you'd want to destroy, and trimming it frees a slot for interaction. In the games where you're both going off, try to let them put their threat into play with Show and Tell while you're putting in Omniscience or Atraxa — matching their threat rather than countering can be correct when you have the more powerful follow-up.
Oops, All Spells! is a fast combo deck that wins by milling its entire library with Balustrade Spy or Undercity Informer, then using Dread Return to reanimate Thassa's Oracle for a Laboratory Maniac-style win, often on turn one or two. Your primary defense is Force of Will backed by Force of Negation to counter the key spell — prioritize countering Balustrade Spy or Undercity Informer before they can trigger the chain. Grafdigger's Cage is your best hate piece as it prevents Dread Return from functioning and shuts down Narcomoeba and Poxwalkers from entering play from the graveyard. Ravenous Trap can exile their graveyard in response to Dread Return for free if they've already filled it. Be aware their sideboard brings in Leyline of the Void against you (irrelevant) and Force of Vigor to destroy your Cage, so try to win before they can interact, as your own combo is faster than theirs in many draws.