Clarion Conqueror shuts down activated abilities of artifacts, creatures, and planeswalkers, locking out Devoted Druid's untap ability, Vizier of Remedies-enabled mana engines, and Agatha's Soul Cauldron's exile ability all at once. Subtlety is cut because its primary combo pieces, Devoted Druid and Vizier of Remedies, are creatures that resolve before we'd ever get to target them with a creature-spell bounce, making it a weak answer to their actual engine. Force of Negation stays in since it can still counter their noncreature combo enablers like Green Sun's Zenith and Nature's Rhythm, both sorceries. Endurance remains strong at flash-blocking their small dorks and disrupting their graveyard-based lines.