Izzet Leyline Aggro goes wide fast with cheap creatures like Elusive Otter, Stadium Headliner, and Slickshot Show-Off, so Split Up's sweeping effect on all tapped or untapped creatures is a strong reset against their board. Avatar's Wrath airbends all other creatures while temporarily locking out casting from anywhere other than their hands, slowing their aggression. Erode is weak here since it gives them a free land, and Practiced Offense is too slow against their low curve. Prioritize efficient sweeper effects over one-for-one removal to keep pace with their wide starts.