Jeskai Ephemerate is a value-grinding control deck built around blinking Augur of Bolas and Mulldrifter with Ephemerate, backed by Skred and Counterspell, so Pyroblast is live to counter or destroy their blue spells and creatures. Their Bender's Waterskin is a reasonable target for Annul if you're on the play against it. This is a long, grindy matchup where both decks want to accrue card advantage, so keep your engine pieces like Lorien Revealed, Brainstorm, and Murmuring Mystic and just trim the weakest cards, Pulse of Murasa and Campfire, for extra interaction. Watch for Ephemerate's rebound resetting their Augur of Bolas triggers a second time.