Izzet Phoenix is an all-in blue-red spells deck trying to enable Arclight Phoenix, so Mystical Dispute is very cheap and efficient against their blue spells like their cantrips and Treasure Cruise, costing just {U} when it targets one. Three Steps Ahead can counter a key spell like Artist's Talent, and it can also copy our own Beza in a pinch, or draw two and discard one when we want value. Spell Snare only hits mana value 2 and misses most of their one-mana cantrips and burn, and Plunder the Trollshaws is too slow against their proactive graveyard-fueling plan, so we prioritize flexible countermagic instead. Keep Temporary Lockdown to catch Picklock Prankster, Artist's Talent and Proft's Eidetic Memory, though it won't touch Arclight Phoenix, and keep No More Lies/Dovin's Veto to stop their key spells.