Izzet Cauldron relies on cheap cantrips and card advantage engines like Prismari Charm and Eddymurk Crab; Go Blank strips two cards and exiles their graveyard, hurting Eddymurk Crab's cost reduction and any flashback-style value. Duress proactively takes Stubborn Denial or counterspells before you commit Sheoldred or Professor Dellian Fel. Graveyard Trespasser's upside is lower here since the opponent isn't heavily graveyard-based, and the single Culling Ritual is awkward against a deck without many cheap permanents worth sweeping. Keep Thoughtseize and Fatal Push as premium interaction against their small threats and removal.

This is the mirror, so proactive discard matters more than ever: Duress strips removal (Fatal Push, Abrupt Decay, Go for the Throat), Culling Ritual, or Professor Dellian Fel before you commit threats. Withering Curse gives all creatures -2/-2, which kills their Badgermole Cub but not Graveyard Trespasser (3/3) or Sentinel of the Nameless City (3/4). It becomes a full sweeper only if you gained life this turn, such as with Dellian's +2 or a Sheoldred trigger, so plan around that and remember it hits your own creatures too. Sentinel is fine but less impactful than discard in a grindy mirror where hand information wins games, and Culling Ritual is a narrow, symmetrical effect that only destroys permanents with mana value 2 or less. Prioritize resolving Sheoldred and Professor Dellian Fel through their Thoughtseize and Duress. Duress can't take Sheoldred since it only hits noncreature cards, but Thoughtseize can, so expect Sheoldred to be exposed to Thoughtseize.

Nykthos Ramp wants to resolve huge threats like Cavalier of Thorns, Storm the Festival hits, and Craterhoof-style finishes; Invoke Despair forces a creature sacrifice and punishes them for going wide or tall with planeswalkers like Kiora. Unlicensed Hearse disrupts their Cavalier of Thorns recursion and graveyard-based value while growing into a real blocker. Badgermole Cub and Sentinel of the Nameless City are too small to matter once they're casting Storm the Festival or landing Leyline of the Guildpact-enabled threats, so they come out for more impactful answers. Keep Thoughtseize and Abrupt Decay to strip their mana dorks and Kiora before they go off.