Mainboard (60)
Creatures (31)
Instants (7)
Enchantments (4)
Boros Energy is a fast creature-based deck that pressures you before your midrange engine comes online. Mystical Dispute is excellent here since nearly every threat they play is red or white, and Collector Ouphe shuts down Galvanic Discharge and limits their artifact synergies. Force of Negation is worse in this matchup because they aren't a combo deck and their threats come down early on mana rather than at instant speed; Fblthp is the weakest card in the deck when you need to interact on the ground. Force of Negation's pitch cost is too high when your hand already needs green cards for Harbinger synergies and you need to stabilize the board quickly.
Jeskai Blink is a blue-heavy interactive deck built around Quantum Riddler, Solitude, and Phelia; Mystical Dispute is nearly free to cast and counters their most important spells including Solitude and Teferi. Consign to Memory handles Quantum Riddler and Phelia triggers that would generate card advantage or dig them deeper. Harbinger of the Seas is a symmetrical pain against their small land count but hurts you more in a grindy matchup where you need your mana; Endurance doesn't answer any specific threat they present and Fblthp is too slow at sorcery speed. The game is decided by who can stick a threat through the opponent's interaction, so prioritize countermagic.
Affinity is an artifact-based deck where Collector Ouphe shuts down Mox Opal, Engineered Explosives, and Mishra's Bauble, neutering their entire engine. Force of Vigor destroys Mox Opal or Urza's Saga tokens for free, while Consign to Memory counters Kappa Cannoneer or Weapons Manufacturing at instant speed. Subtlety is very poor against artifact creatures with no trigger to bounce and Harbinger of the Seas does nothing relevant here; Endurance and Fblthp are too slow to matter when Affinity can assemble a board by turn two. Getting Collector Ouphe into play quickly is your primary goal.