Remove Soul counters their key creature spells on the stack, including Balustrade Spy before its mill trigger or a big Troll of Khazad-dum before it resolves. It can't touch a creature that Dread Return puts onto the battlefield, since that creature is never cast, so Negate is the answer to the reanimation spell itself. Negate answers their noncreature spells like Dread Return, Winding Way, or Lead the Stampede that fuel their ramp-into-threats plan. Prohibit is weaker here since many of their key creatures (Troll of Khazad-dum, Sagu Wildling, Generous Ent) cost well above its kicked threshold, so one copy comes out in favor of a cleaner answer. Keep the full bounce and blink suite: Snap can repeatedly reset their mana dorks and walls, while blink effects re-trigger your own enters-the-battlefield creatures as your card advantage takes over the long game.