Devoted Combo wants to chain Devoted Druid and Green Sun's Zenith into a big Craterhoof Behemoth or Ouroboroid finish, and Nihil Spellbomb plus Extirpate deny Agatha's Soul Cauldron's graveyard exile fuel and any recursion targets. Murderous Cut is a cheap answer to Devoted Druid or Vizier of Remedies before they go off, using our self-mill for delve. We're trading our redundant Surgical Extraction copy and slower mill pieces since interaction matters more than raw speed against a combo deck that can kill us out of nowhere.