Gruul Sligh wants to flood the board with cheap threats and burn you out before the Stasis lock comes online, so the post-board plan adds significant speed bumps: Chill taxes every red spell by two mana, which dramatically slows their ability to both develop their board and threaten your life total in the same turn. Hydroblast counters their burn spells or destroys key red creatures like Grim Lavamancer, while Cursed Totem completely shuts off Lavamancer's activated ability and Mogg Fanatic's sacrifice trigger. Oath of Druids provides an alternate lock plan — they will always have more creatures than you, so it triggers on your upkeep and fetches Akroma, Angel of Wrath, who has protection from red and is effectively immune to their entire removal suite of Lightning Bolt, Incinerate, and Lava Dart. Brain Freeze and Gaea's Blessing are dead cards with no mill interaction in this matchup, Boomerang is too slow when they're deploying multiple threats per turn, and Foil is poor here since pitching lands to counter cheap burn or one-drops is an unfavorable rate.