Izzet Prowess is a sea of cheap noncreature spells, so Mystical Dispute is excellent here, taxing their blue spells (Preordain, Expressive Iteration) for as little as {U} and anything else for {2}{U}, unless they pay {3}. Vexing Bauble shuts down their many free/cheap interactions indirectly by punishing 0-cost tricks like Mishra's Bauble and Mutagenic Growth, while Rest in Peace cuts off Lava Dart's flashback. Lightning Bolt is a weak trade against their 1-2 toughness creatures that are usually already dead to combat math or outclassed by our bigger threats, and one Consign to Memory is enough since Mishra's Bauble is their only colorless spell, and the other things it can hit are triggered abilities like prowess and Cori-Steel Cutter's flurry trigger (the Cutter itself is a red artifact, so it isn't a legal target). Territorial Kavu is often a small, vulnerable body early against their burn-heavy removal suite, so trimming one copy for more targeted interaction is reasonable while keeping the rest of our core engine intact.