Phyrexian Dreadnought is cast as an artifact creature and relies on Stifle to counter its own sacrifice trigger, so there's no clean way to interact with the combo itself beyond racing and disruption. Duress and Cabal Therapy remain excellent at stripping Stifle, Vision Charm, or counterspells before they land, and Cabal Therapy can also name Dreadnought directly. Tormod's Crypt and Phyrexian Furnace don't stop the Dreadnought plan directly, but they pressure their graveyard, which matters for Flash of Insight's flashback (it exiles blue cards from their graveyard, and Gush, Opt and other cheap blue spells fuel it). Tormod's Crypt exiles the whole graveyard, while Phyrexian Furnace picks off cards one at a time and replaces itself when sacrificed, so keep both in mainly as cheap, low-commitment includes. Mesmeric Fiend is weak here since its exiled card returns if it dies to removal or a trade. Plague Spitter does little against a deck with no small creatures to sweep, and its damage would hit my own Birds and Walls. Uktabi Orangutan stays in, because its enter trigger can destroy Dreadnought (an artifact) or Powder Keg. Prioritize discard to clear their hand before they can protect the Dreadnought, and use Survival of the Fittest to find Uktabi Orangutan to destroy an unprotected Dreadnought, or Withered Wretch as a cheap blocker and graveyard hate.

This matchup is a race against their enchantment-based card advantage and lock pieces, so artifact/enchantment removal is paramount: Nantuko Vigilante morphs in cheaply and then flips to destroy an enchantment like Enchantress's Presence, Solitary Confinement, or Sterling Grove, while Uktabi Orangutan can hit Tormod's Crypt or any stray artifact if needed. Phyrexian Furnace exiles cards from their graveyard, slowing Krosan Reclamation loops and denying Compost-style synergy indirectly by thinning their resources, while also cantripping later. Masticore and Krovikan Horror are cut since they're slow, do nothing to their enchantment engine, and don't pressure a deck that can out-draw and stabilize behind Solitary Confinement. Duress and Cabal Therapy remain crucial to strip Sterling Grove or Solitary Confinement before it locks the game, and Survival of the Fittest should prioritize finding Withered Wretch or Bone Shredder for pressure.

Azorius Replenish wins by resolving Opalescence with Parallax Wave or Decree of Silence, so artifact/enchantment destruction is the best answer: Naturalize can destroy Opalescence before the combo turns on or hit Parallax Wave directly, while Nantuko Vigilante morphs in as a cheap blocker and then flips to destroy an enchantment at instant speed relative to their turn. Mesmeric Fiend's disruption is temporary and doesn't stop a resolved Replenish, Krovikan Horror is too slow, and Palinchron dies easily to Swords to Plowshares without advancing your gameplan against their lock pieces. Duress and Cabal Therapy remain critical to strip a Replenish or Opalescence from their hand before it can be cast, since once the enchantments resolve together you're facing a very difficult board to attack into.