Spellementals wins by chaining cheap cantrips into discounted Hearth Elemental and Eddymurk Crab, so Torpor Orb completely shuts off the enters-the-battlefield tap triggers from Eddymurk Crab and blunts their payoffs. Disdainful Stroke snipes Eddymurk Crab and Sunderflock, their biggest tempo and reset threats. Bitter Triumph and Feed the Cycle both ask for extra resources on top of their mana cost (a discard or 3 life, a forage or extra {B}), so trim them for proactive disruption. Requiting Hex stays out of the swap plan: it only destroys creatures with mana value 2 or less, and none of their creatures (Hearth Elemental, Eddymurk Crab, Sunderflock) come close to that.

UR Aggro's clock relies on Slickshot Show-Off growing from cheap spells, and Eddymurk Crab's enters-the-battlefield tap effect is one of their few ways to disrupt a defensive setup. Torpor Orb shuts off the Crab's tap trigger, but it does not stop Show-Off, whose bonus triggers on casting a spell rather than on a creature entering. Requiting Hex (Instant) is a one-mana answer to their mana-value-2-or-less creatures like Elusive Otter and Slickshot Show-Off, and it can gain 2 life if you pay the optional blight cost. Bitter Triumph's additional cost (discard a card or pay 3 life) is awkward against an aggressive deck, so trim it for cheaper interaction. Disdainful Stroke is a lower priority here because it only counters spells with mana value 4 or greater, and Eddymurk Crab is the main one in their deck that qualifies. It cannot counter Burst Lightning, which has mana value 1 even when kicked, or lands. Keep the deck leaning toward efficient one-for-one removal and life gain.

Dimir Midrange relies on Enduring Curiosity and Kaito, Bane of Nightmares for card advantage, so Strategic Betrayal is a good edict here: they must exile a creature they control (exiling means no dies trigger, so Enduring Curiosity can't return as an enchantment if it's the one chosen) and their graveyard. They pick which creature goes, so it is best when they have few creatures. Torpor Orb shuts off Floodpits Drowner and Dream Beavers enters-the-battlefield triggers, a huge tempo loss for them. Duress proactively strips Requiting Hex or Kaito before they can deploy it. Chandra and Three Steps Ahead are cut since this is a grindy mirror-ish matchup where proactive discard and threat denial outperform tempo plays.