This is a mirror-adjacent matchup where both decks share core infrastructure — Leyline of the Guildpact, Scion of Draco, and Leyline Binding — but Domain Zoo disrupts your cascade plan primarily through Consign to Memory and Stubborn Denial (which becomes a hard counter with Ferocious from their large creatures). Mystical Dispute comes in as a one-mana answer to their counterspells and their own blue threats like Subtlety, making it the highest-impact sideboard card here. Tishana's Tidebinder adds a body and can counter Ragavan's triggered ability or Phelia's ETB, stranding their tempo plays. Fire/Ice is the cleanest cut: Ice tapping Ragavan is marginally useful, but Fire dealing 2 damage rarely kills anything relevant when Territorial Kavu and Quantum Riddler dominate their threat base. Prioritize resolving Crashing Footfalls on their end step and keep Force of Negation up to counter Consign to Memory.