Devoted Combo wants to chain free/cheap spells like Green Sun's Zenith, Devoted Druid, and Leyline of Abundance to ramp into Craterhoof Behemoth or Agatha's Soul Cauldron lines; Vexing Bauble taxes and can outright counter any zero-cost activation-adjacent play and slows their mana engine. Claim the Firstborn can steal a small ramp creature like Delighted Halfling or Badgermole Cub before it does its job, denying mana. Cool but Rude adds a steady discard-damage clock to race them if the combo gets disrupted. Ox of Agonas is cut as too slow and clunky against a deck that can end the game quickly once it assembles its pieces.