Domain Zoo is an aggressive creature deck (Ragavan, Wild Nacatl, Territorial Kavu, Scion of Draco) backed by Leyline Binding and burn, so Unholy Heat gives you cheap, efficient removal that can scale to 6 damage with delirium to answer even their bigger threats like Scion of Draco. Fire Magic's Fire mode for {0} clears small creatures like Ragavan, though Wild Nacatl gets +1/+1 from a Mountain and Plains to reach 3 toughness and requires the {5} Firaga mode to sweep. Boomerang Basics is too slow against a deck this fast, and Sewer-veillance Cam doesn't meaningfully impede their attackers. Be mindful that they can also apply pressure with Stubborn Denial as interaction (whereas Consign to Memory can only counter colorless spells or triggered abilities, not your red removal), so try to play removal proactively before they stabilize behind Leyline Binding.