Unholy Heat comes in as cheap, instant-speed interaction against their mana creatures: its 2 damage kills Devoted Druid, Vizier of Remedies, Delighted Halfling, Birds of Paradise and Badgermole Cub, so use it to break up the Druid and Vizier infinite mana combo before it goes off. Ashiok, Dream Render denies them Green Sun's Zenith and Nature's Rhythm's library search ability entirely, which is a huge blow to their toolbox plan, while its -1 also strips their graveyard against Agatha's Soul Cauldron value and Nature's Rhythm's harmonize. Surgical Extraction can only target a card already in a graveyard, so save it for a Devoted Druid or Nature's Rhythm once a copy has landed there, and it also exiles the other copies from their hand and library. Flare of Malice is weak since Walking Ballista and other small permanents dodge the biggest-permanent clause, so cut it along with some Street Wraith for the sideboard disruption.