Doomsday wants to resolve its namesake sorcery and then finish with Thassa's Oracle. Force of Negation is one of our best tools here: it can only counter noncreature spells, so it can't stop Thassa's Oracle, but it can counter Doomsday itself, along with Dark Ritual, Personal Tutor and their cantrips, for free on their turn. Surgical Extraction becomes strong once a Doomsday has been countered: it can then exile the remaining copies from their hand and library, which hurts a deck that depends on a few key cards. Stifle stays in because Thassa's Oracle's enter trigger is a triggered ability, so Stifle can stop the win even after Doomsday resolves. Swords to Plowshares has few worthwhile targets in this matchup, and Consign to Memory is narrower than Stifle, so those get trimmed. Keep Force of Will and Daze at full count to keep disrupting their explosive mana development.