Izzet Prowess wants to go wide and tall quickly with Dragon's Rage Channeler, Monastery Swiftspear, and Slickshot Show-Off; extra Dismember gives cheap, efficient removal for any of their one-toughness-matters threats before they get out of hand, and Wastescape Battlemage's blue kicker bounces an attacker that's grown too large. Cut the lone Emrakul, the Promised End, which is far too slow against their low curve, and trim two Sowing Mycospawn since you need to stabilize quickly rather than durdle for value against a deck that can kill fast.