This is a mirror-adjacent matchup, so Surgical Extraction is excellent for stripping a resolved Murktide Regent's fuel or answering a key card before it can be replayed. Dauthi Voidwalker is an efficient evasive clock that also exiles opposing cards heading to the graveyard, hampering their Nethergoyf and Murktide Regent. Flow State is cut down since card selection is less important than proactive disruption and threats in this grindy mirror. Drown in the Loch is weak early against a deck with an empty graveyard, so we trim one copy for more targeted interaction.

A second Toxic Deluge (paid at X=2) is a premium sweeper against a token-heavy strategy built around Ocelot Pride and Ajani, Nacatl Pariah tokens, wiping their board cheaply. Dauthi Voidwalker races well since it dodges Swords to Plowshares' main downside window less often and pressures life total in a life-gain matchup. Drown in the Loch is weak early when their graveyard is empty, and Kaito is vulnerable to their wide combat math and Wasteland-heavy manabase, so both come out. Keep an eye on Karakas bouncing Tamiyo in creature form.

Consign to Memory is excellent since it counters colorless spells for cheap, hitting things like Lotus Petal-fueled plays and any colorless permanents, while also stopping triggered abilities. The extra Force of Negation lets us fight through their Show and Tell into Atraxa, Grand Unifier or Omniscience plan for free on their turn. Fatal Push does very little against their huge Atraxa, Grand Unifier and combo-oriented gameplan with few small creatures, so we trim it, and Barrowgoyf is a slow clock against a deck racing to assemble Aluren or Show and Tell, so one copy comes out. Force of Will and Thoughtseize remain critical to strip their combo pieces before they resolve.